The Critique of Pure Reason

I. Transcendental Doctrine of Elements

First Part—TRANSCENDENTAL ÆSTHETIC

§ 1. Introductory

SECTION I. OF SPACE

§ 2. Metaphysical Exposition of this Conception.

§ 3. Transcendental Exposition of the Conception of Space.

§ 4. Conclusions from the foregoing Conceptions.

SECTION II. OF TIME

§ 5. Metaphysical Exposition of this Conception.

§ 6. Transcendental Exposition of the Conception of Time.

§ 7. Conclusions from the above Conceptions.

§ 8. Elucidation.

§ 9. General Remarks on Transcendental Æsthetic.

§ 10. Conclusion of the Transcendental Æsthetic.

Second Part—TRANSCENDENTAL LOGIC

Introduction. Idea of a Transcendental Logic

I. Of Logic in General

II. Of Transcendental Logic

III. Of the Division of General Logic into Analytic and Dialectic

IV. Of the Division of Transcendental Logic into Transcendental

Analytic and Dialectic

FIRST DIVISION—TRANSCENDENTAL ANALYTIC

BOOK I. Analytic of Conceptions. § 2

Chapter I. Of the Transcendental Clue to the Discovery of all Pure

Conceptions of the Understanding

Introductory § 3

Section I. Of the Logical Use of the Understanding in General. § 4

Section II. Of the Logical Function of the Understanding in

Judgements. § 5

Section III. Of the Pure Conceptions of the Understanding, or

Categories. § 6

Chapter II. Of the Deduction of the Pure Conception of the

Understanding

Section I. Of the Principles of a Transcendental Deduction in general

§ 9

Transition to the Transcendental Deduction of the Categories. § 10

Section II Transcendental Deduction of the pure Conceptions of the

Understanding.

Of the Possibility of a Conjunction of the manifold representations

given by Sense. § 11.

Of the Originally Synthetical Unity of Apperception. § 12

The Principle of the Synthetical Unity of Apperception is the highest

Principle of all exercise of the Understanding. § 13

What Objective Unity of Self-consciousness is. § 14

The Logical Form of all Judgements consists in the Objective Unity of

Apperception of the Conceptions contained therein. § 15

All Sensuous Intuitions are subject to the Categories, as Conditions

under which alone the manifold Content of them can be united in one

Consciousness. § 16

Observation. § 17

In Cognition, its Application to Objects of Experience is the only

legitimate use of the Category. § 18

Of the Application of the Categories to Objects of the Senses in

general. § 20

Transcendental Deduction of the universally possible employment in

experience of the Pure Conceptions of the Understanding. § 22

Result of this Deduction of the Conceptions of the Understanding. § 23

BOOK II. Analytic of Principles

INTRODUCTION. Of the Transcendental Faculty of judgement in General.

TRANSCENDENTAL DOCTRINE OF THE FACULTY OF JUDGEMENT OR, ANALYTIC OF

PRINCIPLES.

Chapter I. Of the Schematism at of the Pure Conceptions of the

Understanding.

Chapter II. System of all Principles of the Pure Understanding.

Section I. Of the Supreme Principle of all Analytical Judgements.

Section II. Of the Supreme Principle of all Synthetical Judgements.

Section III. Systematic Representation of all Synthetical Principles

of the Pure Understanding.

Chapter III Of the Ground of the Division of all Objects into

Phenomena and Noumena.

APPENDIX.

SECOND DIVISION—TRANSCENDENTAL LOGIC

TRANSCENDENTAL DIALECTIC. INTRODUCTION.

I. Of Transcendental Illusory Appearance.

II. Of Pure Reason as the Seat of Transcendental Illusory Appearance.

TRANSCENDENTAL DIALECTIC—BOOK I—OF THE CONCEPTIONS OF PURE REASON.

Section I—Of Ideas in General.

Section II. Of Transcendental Ideas.

Section III. System of Transcendental Ideas.

TRANSCENDENTAL DIALECTIC—BOOK II—OF THE DIALECTICAL PROCEDURE OF PURE

REASON.

Chapter I. Of the Paralogisms of Pure Reason.

Chapter II. The Antinomy of Pure Reason.

Section I. System of Cosmological Ideas.

Section II. Antithetic of Pure Reason.

Section III. Of the Interest of Reason in these Self-contradictions.

Section IV. Of the necessity imposed upon Pure Reason of presenting a

Solution of its Transcendental Problems.

Section V. Sceptical Exposition of the Cosmological Problems presented

in the four Transcendental Ideas.

Section VI. Transcendental Idealism as the Key to the Solution of Pure

Cosmological Dialectic.

Section VII. Critical Solution of the Cosmological Problem.

Section VIII. Regulative Principle of Pure Reason in relation to the

Cosmological Ideas.

Section IX. Of the Empirical Use of the Regulative Principle of Reason

with regard to the Cosmological Ideas.

I. Solution of the Cosmological Idea of the Totality of the

Composition of Phenomena in the Universe.

II. Solution of the Cosmological Idea of the Totality of the Division

of a Whole given in Intuition.

III. Solution of the Cosmological Idea of the Totality of the

Deduction of Cosmical Events from their Causes.

IV. Solution of the Cosmological Idea of the Totality of the

Dependence of Phenomenal Existences.

Chapter III. The Ideal of Pure Reason.

Section I. Of the Ideal in General.

Section II. Of the Transcendental Ideal (Prototypon Trancendentale).

Section III. Of the Arguments employed by Speculative Reason in Proof

of the Existence of a Supreme Being.

Section IV. Of the Impossibility of an Ontological Proof of the

Existence of God.

Section V. Of the Impossibility of a Cosmological Proof of the

Existence of God.

Section VI. Of the Impossibility of a Physico-Theological Proof.

Section VII. Critique of all Theology based upon Speculative

Principles of Reason.

Appendix. Of the Regulative Employment of the Ideas of Pure Reason.

II. Transcendental Doctrine of Method

Chapter I. The Discipline of Pure Reason.

Section I. The Discipline of Pure Reason in the Sphere of Dogmatism.

Section II. The Discipline of Pure Reason in Polemics.

Section III. The Discipline of Pure Reason in Hypothesis.

Section IV. The Discipline of Pure Reason in Relation to Proofs.

Chapter II. The Canon of Pure Reason.

Section I. Of the Ultimate End of the Pure Use of Reason.

Section II. Of the Ideal of the Summum Bonum as a Determining Ground

of the Ultimate End of Pure Reason.

Section III. Of Opinion, Knowledge, and Belief.

Chapter III. The Architectonic of Pure Reason.

Chapter IV. The History of Pure Reason.

PREFACE TO THE FIRST EDITION 1781

Human reason, in one sphere of its cognition, is called upon to

consider questions, which it cannot decline, as they are presented by

its own nature, but which it cannot answer, as they transcend every

faculty of the mind.

It falls into this difficulty without any fault of its own. It begins

with principles, which cannot be dispensed with in the field of

experience, and the truth and sufficiency of which are, at the same

time, insured by experience. With these principles it rises, in

obedience to the laws of its own nature, to ever higher and more remote

conditions. But it quickly discovers that, in this way, its labours

must remain ever incomplete, because new questions never cease to

present themselves; and thus it finds itself compelled to have recourse

to principles which transcend the region of experience, while they are

regarded by common sense without distrust. It thus falls into confusion

and contradictions, from which it conjectures the presence of latent

errors, which, however, it is unable to discover, because the

principles it employs, transcending the limits of experience, cannot be

tested by that criterion. The arena of these endless contests is called

_Metaphysic_.

Time was, when she was the _queen_ of all the sciences; and, if we take

the will for the deed, she certainly deserves, so far as regards the

high importance of her object-matter, this title of honour. Now, it is

the fashion of the time to heap contempt and scorn upon her; and the

matron mourns, forlorn and forsaken, like Hecuba:

Modo maxima rerum,

Tot generis, natisque potens...

Nunc trahor exul, inops.

—Ovid, Metamorphoses. xiii

At first, her government, under the administration of the _dogmatists_,

was an absolute _despotism_. But, as the legislative continued to show

traces of the ancient barbaric rule, her empire gradually broke up, and

intestine wars introduced the reign of _anarchy;_ while the _sceptics_,

like nomadic tribes, who hate a permanent habitation and settled mode

of living, attacked from time to time those who had organized

themselves into civil communities. But their number was, very happily,

small; and thus they could not entirely put a stop to the exertions of

those who persisted in raising new edifices, although on no settled or

uniform plan. In recent times the hope dawned upon us of seeing those

disputes settled, and the legitimacy of her claims established by a

kind of _physiology_ of the human understanding—that of the celebrated

Locke. But it was found that—although it was affirmed that this

so-called queen could not refer her descent to any higher source than

that of common experience, a circumstance which necessarily brought

suspicion on her claims—as this _genealogy_ was incorrect, she

persisted in the advancement of her claims to sovereignty. Thus

metaphysics necessarily fell back into the antiquated and rotten

constitution of _dogmatism_, and again became obnoxious to the contempt

from which efforts had been made to save it. At present, as all

methods, according to the general persuasion, have been tried in vain,

there reigns nought but weariness and complete _indifferentism_—the

mother of chaos and night in the scientific world, but at the same time

the source of, or at least the prelude to, the re-creation and

reinstallation of a science, when it has fallen into confusion,

obscurity, and disuse from ill directed effort.

For it is in reality vain to profess _indifference_ in regard to such

inquiries, the object of which cannot be indifferent to humanity.

Besides, these pretended _indifferentists_, however much they may try

to disguise themselves by the assumption of a popular style and by

changes on the language of the schools, unavoidably fall into

metaphysical declarations and propositions, which they profess to

regard with so much contempt. At the same time, this indifference,

which has arisen in the world of science, and which relates to that

kind of knowledge which we should wish to see destroyed the last, is a

phenomenon that well deserves our attention and reflection. It is

plainly not the effect of the levity, but of the matured _judgement_[1]

of the age, which refuses to be any longer entertained with illusory

knowledge, It is, in fact, a call to reason, again to undertake the

most laborious of all tasks—that of self-examination, and to establish

a tribunal, which may secure it in its well-grounded claims, while it

pronounces against all baseless assumptions and pretensions, not in an

arbitrary manner, but according to its own eternal and unchangeable

laws. This tribunal is nothing less than the _Critical Investigation of

Pure Reason_.

[1] We very often hear complaints of the shallowness of the present

age, and of the decay of profound science. But I do not think that

those which rest upon a secure foundation, such as mathematics,

physical science, etc., in the least deserve this reproach, but that

they rather maintain their ancient fame, and in the latter case,

indeed, far surpass it. The same would be the case with the other

kinds of cognition, if their principles were but firmly established.

In the absence of this security, indifference, doubt, and finally,

severe criticism are rather signs of a profound habit of thought. Our

age is the age of criticism, to which everything must be subjected.

The sacredness of religion, and the authority of legislation, are by

many regarded as grounds of exemption from the examination of this

tribunal. But, if they are exempted, they become the subjects of just

suspicion, and cannot lay claim to sincere respect, which reason

accords only to that which has stood the test of a free and public

examination.

I do not mean by this a criticism of books and systems, but a critical

inquiry into the faculty of reason, with reference to the cognitions to

which it strives to attain _without the aid of experience;_ in other

words, the solution of the question regarding the possibility or

impossibility of metaphysics, and the determination of the origin, as

well as of the extent and limits of this science. All this must be done

on the basis of principles.

This path—the only one now remaining—has been entered upon by me; and I

flatter myself that I have, in this way, discovered the cause of—and

consequently the mode of removing—all the errors which have hitherto

set reason at variance with itself, in the sphere of non-empirical

thought. I have not returned an evasive answer to the questions of

reason, by alleging the inability and limitation of the faculties of

the mind; I have, on the contrary, examined them completely in the

light of principles, and, after having discovered the cause of the

doubts and contradictions into which reason fell, have solved them to

its perfect satisfaction. It is true, these questions have not been

solved as dogmatism, in its vain fancies and desires, had expected; for

it can only be satisfied by the exercise of magical arts, and of these

I have no knowledge. But neither do these come within the compass of

our mental powers; and it was the duty of philosophy to destroy the

illusions which had their origin in misconceptions, whatever darling

hopes and valued expectations may be ruined by its explanations. My

chief aim in this work has been thoroughness; and I make bold to say

that there is not a single metaphysical problem that does not find its

solution, or at least the key to its solution, here. Pure reason is a

perfect unity; and therefore, if the principle presented by it prove to

be insufficient for the solution of even a single one of those

questions to which the very nature of reason gives birth, we must

reject it, as we could not be perfectly certain of its sufficiency in

the case of the others.

While I say this, I think I see upon the countenance of the reader

signs of dissatisfaction mingled with contempt, when he hears

declarations which sound so boastful and extravagant; and yet they are

beyond comparison more moderate than those advanced by the commonest

author of the commonest philosophical programme, in which the dogmatist

professes to demonstrate the simple nature of the soul, or the

necessity of a primal being. Such a dogmatist promises to extend human

knowledge beyond the limits of possible experience; while I humbly

confess that this is completely beyond my power. Instead of any such

attempt, I confine myself to the examination of reason alone and its

pure thought; and I do not need to seek far for the sum-total of its

cognition, because it has its seat in my own mind. Besides, common

logic presents me with a complete and systematic catalogue of all the

simple operations of reason; and it is my task to answer the question

how far reason can go, without the material presented and the aid

furnished by experience.

So much for the completeness and thoroughness necessary in the

execution of the present task. The aims set before us are not

arbitrarily proposed, but are imposed upon us by the nature of

cognition itself.

The above remarks relate to the _matter_ of our critical inquiry. As

regards the _form_, there are two indispensable conditions, which any

one who undertakes so difficult a task as that of a critique of pure

reason, is bound to fulfil. These conditions are _certitude_ and

_clearness_.

As regards _certitude_, I have fully convinced myself that, in this

sphere of thought, _opinion_ is perfectly inadmissible, and that

everything which bears the least semblance of an hypothesis must be

excluded, as of no value in such discussions. For it is a necessary

condition of every cognition that is to be established upon _à priori_

grounds that it shall be held to be absolutely necessary; much more is

this the case with an attempt to determine all pure _à priori_

cognition, and to furnish the standard—and consequently an example—of

all apodeictic (philosophical) certitude. Whether I have succeeded in

what I professed to do, it is for the reader to determine; it is the

author’s business merely to adduce grounds and reasons, without

determining what influence these ought to have on the mind of his

judges. But, lest anything he may have said may become the innocent

cause of doubt in their minds, or tend to weaken the effect which his

arguments might otherwise produce—he may be allowed to point out those

passages which may occasion mistrust or difficulty, although these do

not concern the main purpose of the present work. He does this solely

with the view of removing from the mind of the reader any doubts which

might affect his judgement of the work as a whole, and in regard to its

ultimate aim.

I know no investigations more necessary for a full insight into the

nature of the faculty which we call _understanding_, and at the same

time for the determination of the rules and limits of its use, than

those undertaken in the second chapter of the “Transcendental

Analytic,” under the title of _Deduction of the Pure Conceptions of the

Understanding;_ and they have also cost me by far the greatest

labour—labour which, I hope, will not remain uncompensated. The view

there taken, which goes somewhat deeply into the subject, has two

sides. The one relates to the objects of the pure understanding, and is

intended to demonstrate and to render comprehensible the objective

validity of its _à priori_ conceptions; and it forms for this reason an

essential part of the Critique. The other considers the pure

understanding itself, its possibility and its powers of cognition—that

is, from a subjective point of view; and, although this exposition is

of great importance, it does not belong essentially to the main purpose

of the work, because the grand question is what and how much can reason

and understanding, apart from experience, cognize, and not, how is the

_faculty of thought_ itself possible? As the latter is an inquiry into

the cause of a given effect, and has thus in it some semblance of an

hypothesis (although, as I shall show on another occasion, this is

really not the fact), it would seem that, in the present instance, I

had allowed myself to enounce a mere _opinion_, and that the reader

must therefore be at liberty to hold a different _opinion_. But I beg

to remind him that, if my subjective deduction does not produce in his

mind the conviction of its certitude at which I aimed, the objective

deduction, with which alone the present work is properly concerned, is

in every respect satisfactory.

As regards _clearness_, the reader has a right to demand, in the first

place, _discursive_ or logical clearness, that is, on the basis of

conceptions, and, secondly, _intuitive_ or æsthetic clearness, by means

of intuitions, that is, by examples or other modes of illustration _in

concreto_. I have done what I could for the first kind of

intelligibility. This was essential to my purpose; and it thus became

the accidental cause of my inability to do complete justice to the

second requirement. I have been almost always at a loss, during the

progress of this work, how to settle this question. Examples and

illustrations always appeared to me necessary, and, in the first sketch

of the Critique, naturally fell into their proper places. But I very

soon became aware of the magnitude of my task, and the numerous

problems with which I should be engaged; and, as I perceived that this

critical investigation would, even if delivered in the driest

_scholastic_ manner, be far from being brief, I found it unadvisable to

enlarge it still more with examples and explanations, which are

necessary only from a _popular_ point of view. I was induced to take

this course from the consideration also that the present work is not

intended for popular use, that those devoted to science do not require

such helps, although they are always acceptable, and that they would

have materially interfered with my present purpose. Abbé Terrasson

remarks with great justice that, if we estimate the size of a work, not

from the number of its pages, but from the time which we require to

make ourselves master of it, it may be said of many a book—_that it

would be much shorter, if it were not so short_. On the other hand, as

regards the comprehensibility of a system of speculative cognition,

connected under a single principle, we may say with equal justice: many

a book would have been much clearer, if it had not been intended to be

so very clear. For explanations and examples, and other helps to

intelligibility, aid us in the comprehension of _parts_, but they

distract the attention, dissipate the mental power of the reader, and

stand in the way of his forming a clear conception of the _whole;_ as

he cannot attain soon enough to a survey of the system, and the

colouring and embellishments bestowed upon it prevent his observing its

articulation or organization—which is the most important consideration

with him, when he comes to judge of its unity and stability.

The reader must naturally have a strong inducement to co-operate with

the present author, if he has formed the intention of erecting a

complete and solid edifice of metaphysical science, according to the

plan now laid before him. Metaphysics, as here represented, is the only

science which admits of completion—and with little labour, if it is

united, in a short time; so that nothing will be left to future

generations except the task of illustrating and applying it

_didactically_. For this science is nothing more than the inventory of

all that is given us by _pure reason_, systematically arranged. Nothing

can escape our notice; for what reason produces from itself cannot lie

concealed, but must be brought to the light by reason itself, so soon

as we have discovered the common principle of the ideas we seek. The

perfect unity of this kind of cognitions, which are based upon pure

conceptions, and uninfluenced by any empirical element, or any peculiar

intuition leading to determinate experience, renders this completeness

not only practicable, but also necessary.

Tecum habita, et nôris quam sit tibi curta supellex.

—Persius. Satirae iv. 52.

Such a system of pure speculative reason I hope to be able to publish

under the title of _Metaphysic of Nature_[2]. The content of this work

(which will not be half so long) will be very much richer than that of

the present Critique, which has to discover the sources of this

cognition and expose the conditions of its possibility, and at the same

time to clear and level a fit foundation for the scientific edifice. In

the present work, I look for the patient hearing and the impartiality

of a _judge;_ in the other, for the good-will and assistance of a

_co-labourer_. For, however complete the list of _principles_ for this

system may be in the Critique, the correctness of the system requires

that no _deduced_ conceptions should be absent. These cannot be

presented _à priori_, but must be gradually discovered; and, while the

_synthesis_ of conceptions has been fully exhausted in the Critique, it

is necessary that, in the proposed work, the same should be the case

with their _analysis_. But this will be rather an amusement than a

labour.

[2] In contradistinction to the Metaphysic of Ethics. This work was

never published.

PREFACE TO THE SECOND EDITION 1787

Whether the treatment of that portion of our knowledge which lies

within the province of pure reason advances with that undeviating

certainty which characterizes the progress of _science_, we shall be at

no loss to determine. If we find those who are engaged in metaphysical

pursuits, unable to come to an understanding as to the method which

they ought to follow; if we find them, after the most elaborate

preparations, invariably brought to a stand before the goal is reached,

and compelled to retrace their steps and strike into fresh paths, we

may then feel quite sure that they are far from having attained to the

certainty of scientific progress and may rather be said to be merely

groping about in the dark. In these circumstances we shall render an

important service to reason if we succeed in simply indicating the path

along which it must travel, in order to arrive at any results—even if

it should be found necessary to abandon many of those aims which,

without reflection, have been proposed for its attainment.

That _Logic_ has advanced in this sure course, even from the earliest

times, is apparent from the fact that, since Aristotle, it has been

unable to advance a step and, thus, to all appearance has reached its

completion. For, if some of the moderns have thought to enlarge its

domain by introducing _psychological_ discussions on the mental

faculties, such as imagination and wit, _metaphysical_, discussions on

the origin of knowledge and the different kinds of certitude, according

to the difference of the objects (idealism, scepticism, and so on), or

_anthropological_ discussions on prejudices, their causes and remedies:

this attempt, on the part of these authors, only shows their ignorance

of the peculiar nature of logical science. We do not enlarge but

disfigure the sciences when we lose sight of their respective limits

and allow them to run into one another. Now logic is enclosed within

limits which admit of perfectly clear definition; it is a science which

has for its object nothing but the exposition and proof of the _formal_

laws of all thought, whether it be _à priori_ or empirical, whatever be

its origin or its object, and whatever the difficulties—natural or

accidental—which it encounters in the human mind.

The early success of logic must be attributed exclusively to the

narrowness of its field, in which abstraction may, or rather must, be

made of all the objects of cognition with their characteristic

distinctions, and in which the understanding has only to deal with

itself and with its own forms. It is, obviously, a much more difficult

task for reason to strike into the sure path of science, where it has

to deal not simply with itself, but with objects external to itself.

Hence, logic is properly only a _propædeutic_—forms, as it were, the

vestibule of the sciences; and while it is necessary to enable us to

form a correct judgement with regard to the various branches of

knowledge, still the acquisition of real, substantive knowledge is to

be sought only in the sciences properly so called, that is, in the

objective sciences.

Now these sciences, if they can be termed rational at all, must contain

elements of _à priori_ cognition, and this cognition may stand in a

twofold relation to its object. Either it may have to _determine_ the

conception of the object—which must be supplied extraneously, or it may

have to _establish its reality_. The former is _theoretical_, the

latter _practical_, rational cognition. In both, the _pure_ or _à

priori_ element must be treated first, and must be carefully

distinguished from that which is supplied from other sources. Any other

method can only lead to irremediable confusion.

_Mathematics_ and _physics_ are the two theoretical sciences which have

to determine their objects _à priori_. The former is purely _à priori_,

the latter is partially so, but is also dependent on other sources of

cognition.

In the earliest times of which history affords us any record,

_mathematics_ had already entered on the sure course of science, among

that wonderful nation, the Greeks. Still it is not to be supposed that

it was as easy for this science to strike into, or rather to construct

for itself, that royal road, as it was for logic, in which reason has

only to deal with itself. On the contrary, I believe that it must have

remained long—chiefly among the Egyptians—in the stage of blind groping

after its true aims and destination, and that it was revolutionized by

the happy idea of one man, who struck out and determined for all time

the path which this science must follow, and which admits of an

indefinite advancement. The history of this intellectual

revolution—much more important in its results than the discovery of the

passage round the celebrated Cape of Good Hope—and of its author, has

not been preserved. But Diogenes Laertius, in naming the supposed

discoverer of some of the simplest elements of geometrical

demonstration—elements which, according to the ordinary opinion, do not

even require to be proved—makes it apparent that the change introduced

by the first indication of this new path, must have seemed of the

utmost importance to the mathematicians of that age, and it has thus

been secured against the chance of oblivion. A new light must have

flashed on the mind of the first man (_Thales_, or whatever may have

been his name) who demonstrated the properties of the _isosceles_

triangle. For he found that it was not sufficient to meditate on the

figure, as it lay before his eyes, or the conception of it, as it

existed in his mind, and thus endeavour to get at the knowledge of its

properties, but that it was necessary to produce these properties, as

it were, by a positive _à priori construction;_ and that, in order to

arrive with certainty at _à priori_ cognition, he must not attribute to

the object any other properties than those which necessarily followed

from that which he had himself, in accordance with his conception,

placed in the object.

A much longer period elapsed before _Physics_ entered on the highway of

science. For it is only about a century and a half since the wise BACON

gave a new direction to physical studies, or rather—as others were

already on the right track—imparted fresh vigour to the pursuit of this

new direction. Here, too, as in the case of mathematics, we find

evidence of a rapid intellectual revolution. In the remarks which

follow I shall confine myself to the _empirical_ side of natural

science.

When GALILEI experimented with balls of a definite weight on the

inclined plane, when TORRICELLI caused the air to sustain a weight

which he had calculated beforehand to be equal to that of a definite

column of water, or when STAHL, at a later period, converted metals

into lime, and reconverted lime into metal, by the addition and

subtraction of certain elements;[3] a light broke upon all natural

philosophers. They learned that reason only perceives that which it

produces after its own design; that it must not be content to follow,

as it were, in the leading-strings of nature, but must proceed in

advance with principles of judgement according to unvarying laws, and

compel nature to reply its questions. For accidental observations, made

according to no preconceived plan, cannot be united under a necessary

law. But it is this that reason seeks for and requires. It is only the

principles of reason which can give to concordant phenomena the

validity of laws, and it is only when experiment is directed by these

rational principles that it can have any real utility. Reason must

approach nature with the view, indeed, of receiving information from

it, not, however, in the character of a pupil, who listens to all that

his master chooses to tell him, but in that of a judge, who compels the

witnesses to reply to those questions which he himself thinks fit to

propose. To this single idea must the revolution be ascribed, by which,

after groping in the dark for so many centuries, natural science was at

length conducted into the path of certain progress.

[3] I do not here follow with exactness the history of the

experimental method, of which, indeed, the first steps are involved in

some obscurity.

We come now to _metaphysics_, a purely speculative science, which

occupies a completely isolated position and is entirely independent of

the teachings of experience. It deals with mere conceptions—not, like

mathematics, with conceptions applied to intuition—and in it, reason is

the pupil of itself alone. It is the oldest of the sciences, and would

still survive, even if all the rest were swallowed up in the abyss of

an all-destroying barbarism. But it has not yet had the good fortune to

attain to the sure scientific method. This will be apparent; if we

apply the tests which we proposed at the outset. We find that reason

perpetually comes to a stand, when it attempts to gain _à priori_ the

perception even of those laws which the most common experience

confirms. We find it compelled to retrace its steps in innumerable

instances, and to abandon the path on which it had entered, because

this does not lead to the desired result. We find, too, that those who

are engaged in metaphysical pursuits are far from being able to agree

among themselves, but that, on the contrary, this science appears to

furnish an arena specially adapted for the display of skill or the

exercise of strength in mock-contests—a field in which no combatant

ever yet succeeded in gaining an inch of ground, in which, at least, no

victory was ever yet crowned with permanent possession.

This leads us to inquire why it is that, in metaphysics, the sure path

of science has not hitherto been found. Shall we suppose that it is

impossible to discover it? Why then should nature have visited our

reason with restless aspirations after it, as if it were one of our

weightiest concerns? Nay, more, how little cause should we have to

place confidence in our reason, if it abandons us in a matter about

which, most of all, we desire to know the truth—and not only so, but

even allures us to the pursuit of vain phantoms, only to betray us in

the end? Or, if the path has only hitherto been missed, what

indications do we possess to guide us in a renewed investigation, and

to enable us to hope for greater success than has fallen to the lot of

our predecessors?

It appears to me that the examples of mathematics and natural

philosophy, which, as we have seen, were brought into their present

condition by a sudden revolution, are sufficiently remarkable to fix

our attention on the essential circumstances of the change which has

proved so advantageous to them, and to induce us to make the experiment

of imitating them, so far as the analogy which, as rational sciences,

they bear to metaphysics may permit. It has hitherto been assumed that

our cognition must conform to the objects; but all attempts to

ascertain anything about these objects _à priori_, by means of

conceptions, and thus to extend the range of our knowledge, have been

rendered abortive by this assumption. Let us then make the experiment

whether we may not be more successful in metaphysics, if we assume that

the objects must conform to our cognition. This appears, at all events,

to accord better with the _possibility_ of our gaining the end we have

in view, that is to say, of arriving at the cognition of objects _à

priori_, of determining something with respect to these objects, before

they are given to us. We here propose to do just what COPERNICUS did in

attempting to explain the celestial movements. When he found that he

could make no progress by assuming that all the heavenly bodies

revolved round the spectator, he reversed the process, and tried the

experiment of assuming that the spectator revolved, while the stars

remained at rest. We may make the same experiment with regard to the

intuition of objects. If the intuition must conform to the nature of

the objects, I do not see how we can know anything of them _à priori_.

If, on the other hand, the object conforms to the nature of our faculty

of intuition, I can then easily conceive the possibility of such an _à

priori_ knowledge. Now as I cannot rest in the mere intuitions, but—if

they are to become cognitions—must refer them, as _representations_, to

something, as _object_, and must determine the latter by means of the

former, here again there are two courses open to me. _Either_, first, I

may assume that the conceptions, by which I effect this determination,

conform to the object—and in this case I am reduced to the same

perplexity as before; _or_ secondly, I may assume that the objects, or,

which is the same thing, that _experience_, in which alone as given

objects they are cognized, conform to my conceptions—and then I am at

no loss how to proceed. For experience itself is a mode of cognition

which requires understanding. Before objects, are given to me, that is,

_à priori_, I must presuppose in myself laws of the understanding which

are expressed in conceptions _à priori_. To these conceptions, then,

all the objects of experience must necessarily conform. Now there are

objects which reason _thinks_, and that necessarily, but which cannot

be given in experience, or, at least, cannot be given _so_ as reason

thinks them. The attempt to think these objects will hereafter furnish

an excellent test of the new method of thought which we have adopted,

and which is based on the principle that we only cognize in things _à

priori_ that which we ourselves place in them.[4]

[4] This method, accordingly, which we have borrowed from the natural

philosopher, consists in seeking for the elements of pure reason in

that _which admits of confirmation or refutation by experiment_. Now

the propositions of pure reason, especially when they transcend the

limits of possible experience, do not admit of our making any

experiment with their _objects_, as in natural science. Hence, with

regard to those _conceptions_ and _principles_ which we assume _à

priori_, our only course will be to view them from two different

sides. We must regard one and the same conception, _on the one hand_,

in relation to experience as an object of the senses and of the

understanding, _on the other hand_, in relation to reason, isolated

and transcending the limits of experience, as an object of mere

thought. Now if we find that, when we regard things from this double

point of view, the result is in harmony with the principle of pure

reason, but that, when we regard them from a single point of view,

reason is involved in self-contradiction, then the experiment will

establish the correctness of this distinction.

This attempt succeeds as well as we could desire, and promises to

metaphysics, in its first part—that is, where it is occupied with

conceptions _à priori_, of which the corresponding objects may be given

in experience—the certain course of science. For by this new method we

are enabled perfectly to explain the possibility of _à priori_

cognition, and, what is more, to demonstrate satisfactorily the laws

which lie _à priori_ at the foundation of nature, as the sum of the

objects of experience—neither of which was possible according to the

procedure hitherto followed. But from this deduction of the faculty of

_à priori_ cognition in the first part of metaphysics, we derive a

surprising result, and one which, to all appearance, militates against

the great end of metaphysics, as treated in the second part. For we

come to the conclusion that our faculty of cognition is unable to

transcend the limits of possible experience; and yet this is precisely

the most essential object of this science. The estimate of our rational

cognition _à priori_ at which we arrive is that it has only to do with

phenomena, and that things in themselves, while possessing a real

existence, lie beyond its sphere. Here we are enabled to put the

justice of this estimate to the test. For that which of necessity

impels us to transcend the limits of experience and of all phenomena is

the _unconditioned_, which reason absolutely requires in things as they

are in themselves, in order to complete the series of conditions. Now,

if it appears that when, on the one hand, we assume that our cognition

conforms to its objects as things in themselves, _the unconditioned

cannot be thought without contradiction_, and that when, on the other

hand, we assume that our representation of things as they are given to

us, does not conform to these things as they are in themselves, but

that these objects, as phenomena, conform to our mode of

representation, _the contradiction disappears:_ we shall then be

convinced of the truth of that which we began by assuming for the sake

of experiment; we may look upon it as established that the

unconditioned does not lie in things as we know them, or as they are

given to us, but in things as they are in themselves, beyond the range

of our cognition.[5]

[5] This experiment of pure reason has a great similarity to that of

the _Chemists_, which they term the experiment of _reduction_, or,

more usually, the _synthetic_ process. The _analysis_ of the

metaphysician separates pure cognition _à priori_ into two

heterogeneous elements, viz., the cognition of things as phenomena,

and of things in themselves. _Dialectic_ combines these again into

harmony with the necessary rational idea of the unconditioned, and

finds that this harmony never results except through the above

distinction, which is, therefore, concluded to be just.

But, after we have thus denied the power of speculative reason to make

any progress in the sphere of the supersensible, it still remains for

our consideration whether data do not exist in _practical_ cognition

which may enable us to determine the transcendent conception of the

unconditioned, to rise beyond the limits of all possible experience

from a _practical_ point of view, and thus to satisfy the great ends of

metaphysics. Speculative reason has thus, at least, made room for such

an extension of our knowledge: and, if it must leave this space vacant,

still it does not rob us of the liberty to fill it up, if we can, by

means of practical data—nay, it even challenges us to make the

attempt.[6]

[6] So the central laws of the movements of the heavenly bodies

established the truth of that which Copernicus, first, assumed only as

a hypothesis, and, at the same time, brought to light that invisible

force (Newtonian attraction) which holds the universe together. The

latter would have remained forever undiscovered, if Copernicus had not

ventured on the experiment—contrary to the senses but still just—of

looking for the observed movements not in the heavenly bodies, but in

the spectator. In this Preface I treat the new metaphysical method as

a hypothesis with the view of rendering apparent the first attempts at

such a change of method, which are always hypothetical. But in the

Critique itself it will be demonstrated, not hypothetically, but

apodeictically, from the nature of our representations of space and

time, and from the elementary conceptions of the understanding.

This attempt to introduce a complete revolution in the procedure of

metaphysics, after the _example_ of the geometricians and natural

philosophers, constitutes the aim of the Critique of Pure Speculative

Reason. It is a treatise on the method to be followed, not a system of

the science itself. But, at the same time, it marks out and defines

both the external boundaries and the internal structure of this

science. For pure speculative reason has this peculiarity, that, in

choosing the various objects of thought, it is able to define the

limits of its own faculties, and even to give a complete enumeration of

the possible modes of proposing problems to itself, and thus to sketch

out the entire system of metaphysics. For, on the one hand, in

cognition _à priori_, nothing must be attributed to the objects but

what the thinking subject derives from itself; and, on the other hand,

reason is, in regard to the principles of cognition, a perfectly

distinct, independent unity, in which, as in an organized body, every

member exists for the sake of the others, and all for the sake of each,

so that no principle can be viewed, with safety, in one relationship,

unless it is, at the same time, viewed in relation to the total use of

pure reason. Hence, too, metaphysics has this singular advantage—an

advantage which falls to the lot of no other science which has to do

with _objects_—that, if once it is conducted into the sure path of

science, by means of this criticism, it can then take in the whole

sphere of its cognitions, and can thus complete its work, and leave it

for the use of posterity, as a capital which can never receive fresh

accessions. For metaphysics has to deal only with principles and with

the limitations of its own employment as determined by these

principles. To this perfection it is, therefore, bound, as the

fundamental science, to attain, and to it the maxim may justly be

applied:

Nil actum reputans, si quid superesset agendum.

But, it will be asked, what kind of a treasure is this that we propose

to bequeath to posterity? What is the real value of this system of

metaphysics, purified by criticism, and thereby reduced to a permanent

condition? A cursory view of the present work will lead to the

supposition that its use is merely _negative_, that it only serves to

warn us against venturing, with speculative reason, beyond the limits

of experience. This is, in fact, its primary use. But this, at once,

assumes a _positive_ value, when we observe that the principles with

which speculative reason endeavours to transcend its limits lead

inevitably, not to the _extension_, but to the _contraction_ of the use

of reason, inasmuch as they threaten to extend the limits of

sensibility, which is their proper sphere, over the entire realm of

thought and, thus, to supplant the pure (practical) use of reason. So

far, then, as this criticism is occupied in confining speculative

reason within its proper bounds, it is only negative; but, inasmuch as

it thereby, at the same time, removes an obstacle which impedes and

even threatens to destroy the use of practical reason, it possesses a

positive and very important value. In order to admit this, we have only

to be convinced that there is an absolutely necessary use of pure

reason—the moral use—in which it inevitably transcends the limits of

sensibility, without the aid of speculation, requiring only to be

insured against the effects of a speculation which would involve it in

contradiction with itself. To deny the positive advantage of the

service which this criticism renders us would be as absurd as to

maintain that the system of police is productive of no positive

benefit, since its main business is to prevent the violence which

citizen has to apprehend from citizen, that so each may pursue his

vocation in peace and security. That space and time are only forms of

sensible intuition, and hence are only conditions of the existence of

things as phenomena; that, moreover, we have no conceptions of the

understanding, and, consequently, no elements for the cognition of

things, except in so far as a corresponding intuition can be given to

these conceptions; that, accordingly, we can have no cognition of an

object, as a thing in itself, but only as an object of sensible

intuition, that is, as phenomenon—all this is proved in the analytical

part of the Critique; and from this the limitation of all possible

speculative cognition to the mere objects of _experience_, follows as a

necessary result. At the same time, it must be carefully borne in mind

that, while we surrender the power of _cognizing_, we still reserve the

power of _thinking_ objects, as things in themselves.[7] For,

otherwise, we should require to affirm the existence of an appearance,

without something that appears—which would be absurd. Now let us

suppose, for a moment, that we had not undertaken this criticism and,

accordingly, had not drawn the necessary distinction between things as

objects of experience and things as they are in themselves. The

principle of causality, and, by consequence, the mechanism of nature as

determined by causality, would then have absolute validity in relation

to all things as efficient causes. I should then be unable to assert,

with regard to one and the same being, e.g., the human soul, that its

will is _free_, and yet, at the same time, subject to natural

necessity, that is, _not free_, without falling into a palpable

contradiction, for in both propositions I should take the soul in _the

same signification_, as a thing in general, as a thing in itself—as,

without previous criticism, I could not but take it. Suppose now, on

the other hand, that we _have_ undertaken this criticism, and have

learnt that an object may be taken in _two senses_, first, as a

phenomenon, secondly, as a thing in itself; and that, according to the

deduction of the conceptions of the understanding, the principle of

causality has reference only to things in the first sense. We then see

how it does not involve any contradiction to assert, on the one hand,

that the will, in the phenomenal sphere—in visible action—is

necessarily obedient to the law of nature, and, in so far, _not free;_

and, on the other hand, that, as belonging to a thing in itself, it is

not subject to that law, and, accordingly, is _free_. Now, it is true

that I cannot, by means of speculative reason, and still less by

empirical observation, _cognize_ my soul as a thing in itself and

consequently, cannot cognize liberty as the property of a being to

which I ascribe effects in the world of sense. For, to do so, I must

cognize this being as existing, and yet not in time, which—since I

cannot support my conception by any intuition—is impossible. At the

same time, while I cannot _cognize_, I can quite well _think_ freedom,

that is to say, my representation of it involves at least no

contradiction, if we bear in mind the critical distinction of the two

modes of representation (the sensible and the intellectual) and the

consequent limitation of the conceptions of the pure understanding and

of the principles which flow from them. Suppose now that morality

necessarily presupposed liberty, in the strictest sense, as a property

of our will; suppose that reason contained certain practical, original

principles _à priori_, which were absolutely impossible without this

presupposition; and suppose, at the same time, that speculative reason

had proved that liberty was incapable of being thought at all. It would

then follow that the moral presupposition must give way to the

speculative affirmation, the opposite of which involves an obvious

contradiction, and that _liberty_ and, with it, morality must yield to

the _mechanism of nature;_ for the negation of morality involves no

contradiction, except on the presupposition of liberty. Now morality

does not require the speculative cognition of liberty; it is enough

that I can think it, that its conception involves no contradiction,

that it does not interfere with the mechanism of nature. But even this

requirement we could not satisfy, if we had not learnt the twofold

sense in which things may be taken; and it is only in this way that the

doctrine of morality and the doctrine of nature are confined within

their proper limits. For this result, then, we are indebted to a

criticism which warns us of our unavoidable ignorance with regard to

things in themselves, and establishes the necessary limitation of our

theoretical _cognition_ to mere phenomena.

[7] In order to _cognize_ an object, I must be able to prove its

possibility, either from its reality as attested by experience, or _à

priori_, by means of reason. But I can _think_ what I please, provided

only I do not contradict myself; that is, provided my conception is a

possible thought, though I may be unable to answer for the existence

of a corresponding object in the sum of possibilities. But something

more is required before I can attribute to such a conception objective

validity, that is real possibility—the other possibility being merely

logical. We are not, however, confined to theoretical sources of

cognition for the means of satisfying this additional requirement, but

may derive them from practical sources.

The positive value of the critical principles of pure reason in

relation to the conception of _God_ and of the _simple nature_ of the

_soul_, admits of a similar exemplification; but on this point I shall

not dwell. I cannot even make the assumption—as the practical interests

of morality require—of God, freedom, and immortality, if I do not

deprive speculative reason of its pretensions to transcendent insight.

For to arrive at these, it must make use of principles which, in fact,

extend only to the objects of possible experience, and which cannot be

applied to objects beyond this sphere without converting them into

phenomena, and thus rendering the _practical extension_ of pure reason

impossible. I must, therefore, abolish _knowledge_, to make room for

_belief_. The dogmatism of metaphysics, that is, the presumption that

it is possible to advance in metaphysics without previous criticism, is

the true source of the unbelief (always dogmatic) which militates

against morality.

Thus, while it may be no very difficult task to bequeath a legacy to

posterity, in the shape of a system of metaphysics constructed in

accordance with the Critique of Pure Reason, still the value of such a

bequest is not to be depreciated. It will render an important service

to reason, by substituting the certainty of scientific method for that

random groping after results without the guidance of principles, which

has hitherto characterized the pursuit of metaphysical studies. It will

render an important service to the inquiring mind of youth, by leading

the student to apply his powers to the cultivation of genuine science,

instead of wasting them, as at present, on speculations which can never

lead to any result, or on the idle attempt to invent new ideas and

opinions. But, above all, it will confer an inestimable benefit on

morality and religion, by showing that all the objections urged against

them may be silenced for ever by the _Socratic_ method, that is to say,

by proving the ignorance of the objector. For, as the world has never

been, and, no doubt, never will be without a system of metaphysics of

one kind or another, it is the highest and weightiest concern of

philosophy to render it powerless for harm, by closing up the sources

of error.

This important change in the field of the sciences, this loss of its

fancied possessions, to which speculative reason must submit, does not

prove in any way detrimental to the general interests of humanity. The

advantages which the world has derived from the teachings of pure

reason are not at all impaired. The loss falls, in its whole extent, on

the _monopoly of the schools_, but does not in the slightest degree

touch the _interests of mankind_. I appeal to the most obstinate

dogmatist, whether the proof of the continued existence of the soul

after death, derived from the simplicity of its substance; of the

freedom of the will in opposition to the general mechanism of nature,

drawn from the subtle but impotent distinction of subjective and

objective practical necessity; or of the existence of God, deduced from

the conception of an _ens realissimum_—the contingency of the

changeable, and the necessity of a prime mover, has ever been able to

pass beyond the limits of the schools, to penetrate the public mind, or

to exercise the slightest influence on its convictions. It must be

admitted that this has not been the case and that, owing to the

unfitness of the common understanding for such subtle speculations, it

can never be expected to take place. On the contrary, it is plain that

_the hope of a future life_ arises from the feeling, which exists in

the breast of every man, that the temporal is inadequate to meet and

satisfy the demands of his nature. In like manner, it cannot be doubted

that the clear exhibition of duties in opposition to all the claims of

inclination, gives rise to the consciousness of _freedom_, and that the

glorious order, beauty, and providential care, everywhere displayed in

nature, give rise to the belief in a wise and great Author of the

Universe. Such is the genesis of these general convictions of mankind,

so far as they depend on rational grounds; and this public property not

only remains undisturbed, but is even raised to greater importance, by

the doctrine that the schools have no right to arrogate to themselves a

more profound insight into a matter of general human concernment than

that to which the great mass of men, ever held by us in the highest

estimation, can without difficulty attain, and that the schools should,

therefore, confine themselves to the elaboration of these universally

comprehensible and, from a moral point of view, amply satisfactory

proofs. The change, therefore, affects only the arrogant pretensions of

the schools, which would gladly retain, in their own exclusive

possession, the key to the truths which they impart to the public.

Quod mecum nescit, solus vult scire videri.

At the same time it does not deprive the speculative philosopher of his

just title to be the sole depositor of a science which benefits the

public without its knowledge—I mean, the Critique of Pure Reason. This

can never become popular and, indeed, has no occasion to be so; for

finespun arguments in favour of useful truths make just as little

impression on the public mind as the equally subtle objections brought

against these truths. On the other hand, since both inevitably force

themselves on every man who rises to the height of speculation, it

becomes the manifest duty of the schools to enter upon a thorough

investigation of the rights of speculative reason and, thus, to prevent

the scandal which metaphysical controversies are sure, sooner or later,

to cause even to the masses. It is only by criticism that

metaphysicians (and, as such, theologians too) can be saved from these

controversies and from the consequent perversion of their doctrines.

Criticism alone can strike a blow at the root of materialism, fatalism,

atheism, free-thinking, fanaticism, and superstition, which are

universally injurious—as well as of idealism and scepticism, which are

dangerous to the schools, but can scarcely pass over to the public. If

governments think proper to interfere with the affairs of the learned,

it would be more consistent with a wise regard for the interests of

science, as well as for those of society, to favour a criticism of this

kind, by which alone the labours of reason can be established on a firm

basis, than to support the ridiculous despotism of the schools, which

raise a loud cry of danger to the public over the destruction of

cobwebs, of which the public has never taken any notice, and the loss

of which, therefore, it can never feel.

This critical science is not opposed to the _dogmatic procedure_ of

reason in pure cognition; for pure cognition must always be dogmatic,

that is, must rest on strict demonstration from sure principles _à

priori_—but to _dogmatism_, that is, to the presumption that it is

possible to make any progress with a pure cognition, derived from

(philosophical) conceptions, according to the principles which reason

has long been in the habit of employing—without first inquiring in what

way and by what right reason has come into the possession of these

principles. Dogmatism is thus the dogmatic procedure of pure reason

_without previous criticism of its own powers_, and in opposing this

procedure, we must not be supposed to lend any countenance to that

loquacious shallowness which arrogates to itself the name of

popularity, nor yet to scepticism, which makes short work with the

whole science of metaphysics. On the contrary, our criticism is the

necessary preparation for a thoroughly scientific system of metaphysics

which must perform its task entirely _à priori_, to the complete

satisfaction of speculative reason, and must, therefore, be treated,

not popularly, but scholastically. In carrying out the plan which the

Critique prescribes, that is, in the future system of metaphysics, we

must have recourse to the strict method of the celebrated WOLF, the

greatest of all dogmatic philosophers. He was the first to point out

the necessity of establishing fixed principles, of clearly defining our

conceptions, and of subjecting our demonstrations to the most severe

scrutiny, instead of rashly jumping at conclusions. The example which

he set served to awaken that spirit of profound and thorough

investigation which is not yet extinct in Germany. He would have been

peculiarly well fitted to give a truly scientific character to

metaphysical studies, had it occurred to him to prepare the field by a

criticism of the _organum_, that is, of pure reason itself. That he

failed to perceive the necessity of such a procedure must be ascribed

to the dogmatic mode of thought which characterized his age, and on

this point the philosophers of his time, as well as of all previous

times, have nothing to reproach each other with. Those who reject at

once the method of Wolf, and of the Critique of Pure Reason, can have

no other aim but to shake off the fetters of _science_, to change

labour into sport, certainty into opinion, and philosophy into

philodoxy.

In this _second edition_, I have endeavoured, as far as possible, to

remove the difficulties and obscurity which, without fault of mine

perhaps, have given rise to many misconceptions even among acute

thinkers. In the propositions themselves, and in the demonstrations by

which they are supported, as well as in the form and the entire plan of

the work, I have found nothing to alter; which must be attributed

partly to the long examination to which I had subjected the whole

before offering it to the public and partly to the nature of the case.

For pure speculative reason is an organic structure in which there is

nothing isolated or independent, but every Single part is essential to

all the rest; and hence, the slightest imperfection, whether defect or

positive error, could not fail to betray itself in use. I venture,

further, to hope, that this system will maintain the same unalterable

character for the future. I am led to entertain this confidence, not by

vanity, but by the evidence which the equality of the result affords,

when we proceed, first, from the simplest elements up to the complete

whole of pure reason and, and then, backwards from the whole to each

part. We find that the attempt to make the slightest alteration, in any

part, leads inevitably to contradictions, not merely in this system,

but in human reason itself. At the same time, there is still much room

for improvement in the _exposition_ of the doctrines contained in this

work. In the present edition, I have endeavoured to remove

misapprehensions of the æsthetical part, especially with regard to the

conception of time; to clear away the obscurity which has been found in

the deduction of the conceptions of the understanding; to supply the

supposed want of sufficient evidence in the demonstration of the

principles of the pure understanding; and, lastly, to obviate the

misunderstanding of the paralogisms which immediately precede the

Rational Psychology. Beyond this point—the end of the second main

division of the “Transcendental Dialectic”—I have not extended my

alterations,[8] partly from want of time, and partly because I am not

aware that any portion of the remainder has given rise to

misconceptions among intelligent and impartial critics, whom I do not

here mention with that praise which is their due, but who will find

that their suggestions have been attended to in the work itself.

[8] The only addition, properly so called—and that only in the method

of proof—which I have made in the present edition, consists of a new

refutation of psychological _Idealism_, and a strict demonstration—the

only one possible, as I believe—of the objective reality of external

intuition. However harmless idealism may be considered—although in

reality it is not so—in regard to the essential ends of metaphysics,

it must still remain a scandal to philosophy and to the general human

reason to be obliged to assume, as an article of mere belief, the

existence of things external to ourselves (from which, yet, we derive

the whole material of cognition for the internal sense), and not to be

able to oppose a satisfactory proof to any one who may call it in

question. As there is some obscurity of expression in the

demonstration as it stands in the text, I propose to alter the passage

in question as follows: “But this permanent cannot be an intuition in

me. For all the determining grounds of my existence which can be found

in me are representations and, as such, do themselves require a

permanent, distinct from them, which may determine my existence in

relation to their changes, that is, my existence in time, wherein they

change.” It may, probably, be urged in opposition to this proof that,

after all, I am only conscious immediately of that which is in me,

that is, of my _representation_ of external things, and that,

consequently, it must always remain uncertain whether anything

corresponding to this representation does or does not exist externally

to me. But I am conscious, through internal _experience_, of my

_existence in time_ (consequently, also, of the determinability of the

former in the latter), and that is more than the simple consciousness

of my representation. It is, in fact, the same as the _empirical

consciousness of my existence_, which can only be determined in

relation to something, which, while connected with my existence, is

_external to me_. This consciousness of my existence in time is,

therefore, identical with the consciousness of a relation to something

external to me, and it is, therefore, experience, not fiction, sense,

not imagination, which inseparably connects the external with my

internal sense. For the external sense is, in itself, the relation of

intuition to something real, external to me; and the reality of this

something, as opposed to the mere imagination of it, rests solely on

its inseparable connection with internal experience as the condition

of its possibility. If with the _intellectual consciousness_ of my

existence, in the representation: _I am_, which accompanies all my

judgements, and all the operations of my understanding, I could, at

the same time, connect a determination of my existence by

_intellectual intuition_, then the consciousness of a relation to

something external to me would not be necessary. But the internal

intuition in which alone my existence can be determined, though

preceded by that purely intellectual consciousness, is itself sensible

and attached to the condition of time. Hence this determination of my

existence, and consequently my internal experience itself, must depend

on something permanent which is not in me, which can be, therefore,

only in something external to me, to which I must look upon myself as

being related. Thus the reality of the external sense is necessarily

connected with that of the internal, in order to the possibility of

experience in general; that is, I am just as certainly conscious that

there are things external to me related to my sense as I am that I

myself exist as determined in time. But in order to ascertain to what

given intuitions objects, external me, really correspond, in other

words, what intuitions belong to the external sense and not to

imagination, I must have recourse, in every particular case, to those

rules according to which experience in general (even internal

experience) is distinguished from imagination, and which are always

based on the proposition that there really is an external

experience.—We may add the remark that the representation of something

_permanent_ in existence, is not the same thing as the _permanent

representation;_ for a representation may be very variable and

changing—as all our representations, even that of matter, are—and yet

refer to something permanent, which must, therefore, be distinct from

all my representations and external to me, the existence of which is

necessarily included in the determination of my own existence, and

with it constitutes _one_ experience—an experience which would not

even be possible internally, if it were not also at the same time, in

part, external. To the question _How?_ we are no more able to reply,

than we are, in general, to think the stationary in time, the

coexistence of which with the variable, produces the conception of

change.

In attempting to render the exposition of my views as intelligible as

possible, I have been compelled to leave out or abridge various

passages which were not essential to the completeness of the work, but

which many readers might consider useful in other respects, and might

be unwilling to miss. This trifling loss, which could not be avoided

without swelling the book beyond due limits, may be supplied, at the

pleasure of the reader, by a comparison with the first edition, and

will, I hope, be more than compensated for by the greater clearness of

the exposition as it now stands.

I have observed, with pleasure and thankfulness, in the pages of

various reviews and treatises, that the spirit of profound and thorough

investigation is not extinct in Germany, though it may have been

overborne and silenced for a time by the fashionable tone of a licence

in thinking, which gives itself the airs of genius, and that the

difficulties which beset the paths of criticism have not prevented

energetic and acute thinkers from making themselves masters of the

science of pure reason to which these paths conduct—a science which is

not popular, but scholastic in its character, and which alone can hope

for a lasting existence or possess an abiding value. To these deserving

men, who so happily combine profundity of view with a talent for lucid

exposition—a talent which I myself am not conscious of possessing—I

leave the task of removing any obscurity which may still adhere to the

statement of my doctrines. For, in this case, the danger is not that of

being refuted, but of being misunderstood. For my own part, I must

henceforward abstain from controversy, although I shall carefully

attend to all suggestions, whether from friends or adversaries, which

may be of use in the future elaboration of the system of this

Propædeutic. As, during these labours, I have advanced pretty far in

years this month I reach my sixty-fourth year—it will be necessary for

me to economize time, if I am to carry out my plan of elaborating the

metaphysics of nature as well as of morals, in confirmation of the

correctness of the principles established in this Critique of Pure

Reason, both speculative and practical; and I must, therefore, leave

the task of clearing up the obscurities of the present work—inevitable,

perhaps, at the outset—as well as, the defence of the whole, to those

deserving men, who have made my system their own. A philosophical

system cannot come forward armed at all points like a mathematical

treatise, and hence it may be quite possible to take objection to

particular passages, while the organic structure of the system,

considered as a unity, has no danger to apprehend. But few possess the

ability, and still fewer the inclination, to take a comprehensive view

of a new system. By confining the view to particular passages, taking

these out of their connection and comparing them with one another, it

is easy to pick out apparent contradictions, especially in a work

written with any freedom of style. These contradictions place the work

in an unfavourable light in the eyes of those who rely on the judgement

of others, but are easily reconciled by those who have mastered the

idea of the whole. If a theory possesses stability in itself, the

action and reaction which seemed at first to threaten its existence

serve only, in the course of time, to smooth down any superficial

roughness or inequality, and—if men of insight, impartiality, and truly

popular gifts, turn their attention to it—to secure to it, in a short

time, the requisite elegance also.

KÖNIGSBERG, _April_ 1787.

Introduction

I. Of the difference between Pure and Empirical Knowledge

That all our knowledge begins with experience there can be no doubt.

For how is it possible that the faculty of cognition should be awakened

into exercise otherwise than by means of objects which affect our

senses, and partly of themselves produce representations, partly rouse

our powers of understanding into activity, to compare to connect, or to

separate these, and so to convert the raw material of our sensuous

impressions into a knowledge of objects, which is called experience? In

respect of time, therefore, no knowledge of ours is antecedent to

experience, but begins with it.

But, though all our knowledge begins with experience, it by no means

follows that all arises out of experience. For, on the contrary, it is

quite possible that our empirical knowledge is a compound of that which

we receive through impressions, and that which the faculty of cognition

supplies from itself (sensuous impressions giving merely the occasion),

an addition which we cannot distinguish from the original element given

by sense, till long practice has made us attentive to, and skilful in

separating it. It is, therefore, a question which requires close

investigation, and not to be answered at first sight, whether there

exists a knowledge altogether independent of experience, and even of

all sensuous impressions? Knowledge of this kind is called à priori, in

contradistinction to empirical knowledge, which has its sources à

posteriori, that is, in experience.

But the expression, “à priori,” is not as yet definite enough

adequately to indicate the whole meaning of the question above started.

For, in speaking of knowledge which has its sources in experience, we

are wont to say, that this or that may be known à priori, because we do

not derive this knowledge immediately from experience, but from a

general rule, which, however, we have itself borrowed from experience.

Thus, if a man undermined his house, we say, “he might know à priori

that it would have fallen;” that is, he needed not to have waited for

the experience that it did actually fall. But still, à priori, he could

not know even this much. For, that bodies are heavy, and, consequently,

that they fall when their supports are taken away, must have been known

to him previously, by means of experience.

By the term “knowledge à priori,” therefore, we shall in the sequel

understand, not such as is independent of this or that kind of

experience, but such as is absolutely so of all experience. Opposed to

this is empirical knowledge, or that which is possible only à

posteriori, that is, through experience. Knowledge à priori is either

pure or impure. Pure knowledge à priori is that with which no empirical

element is mixed up. For example, the proposition, “Every change has a

cause,” is a proposition à priori, but impure, because change is a

conception which can only be derived from experience.

II. The Human Intellect, even in an Unphilosophical State, is in

Possession of Certain Cognitions “à priori”.

The question now is as to a criterion, by which we may securely

distinguish a pure from an empirical cognition. Experience no doubt

teaches us that this or that object is constituted in such and such a

manner, but not that it could not possibly exist otherwise. Now, in the

first place, if we have a proposition which contains the idea of

necessity in its very conception, it is priori. If, moreover, it is not

derived from any other proposition, unless from one equally involving

the idea of necessity, it is absolutely priori. Secondly, an empirical

judgement never exhibits strict and absolute, but only assumed and

comparative universality (by induction); therefore, the most we can say

is—so far as we have hitherto observed, there is no exception to this

or that rule. If, on the other hand, a judgement carries with it strict

and absolute universality, that is, admits of no possible exception, it

is not derived from experience, but is valid absolutely à priori.

Empirical universality is, therefore, only an arbitrary extension of

validity, from that which may be predicated of a proposition valid in

most cases, to that which is asserted of a proposition which holds good

in all; as, for example, in the affirmation, “All bodies are heavy.”

When, on the contrary, strict universality characterizes a judgement,

it necessarily indicates another peculiar source of knowledge, namely,

a faculty of cognition à priori. Necessity and strict universality,

therefore, are infallible tests for distinguishing pure from empirical

knowledge, and are inseparably connected with each other. But as in the

use of these criteria the empirical limitation is sometimes more easily

detected than the contingency of the judgement, or the unlimited

universality which we attach to a judgement is often a more convincing

proof than its necessity, it may be advisable to use the criteria

separately, each being by itself infallible.

Now, that in the sphere of human cognition we have judgements which are

necessary, and in the strictest sense universal, consequently pure à

priori, it will be an easy matter to show. If we desire an example from

the sciences, we need only take any proposition in mathematics. If we

cast our eyes upon the commonest operations of the understanding, the

proposition, “Every change must have a cause,” will amply serve our

purpose. In the latter case, indeed, the conception of a cause so

plainly involves the conception of a necessity of connection with an

effect, and of a strict universality of the law, that the very notion

of a cause would entirely disappear, were we to derive it, like Hume,

from a frequent association of what happens with that which precedes;

and the habit thence originating of connecting representations—the

necessity inherent in the judgement being therefore merely subjective.

Besides, without seeking for such examples of principles existing à

priori in cognition, we might easily show that such principles are the

indispensable basis of the possibility of experience itself, and

consequently prove their existence à priori. For whence could our

experience itself acquire certainty, if all the rules on which it

depends were themselves empirical, and consequently fortuitous? No one,

therefore, can admit the validity of the use of such rules as first

principles. But, for the present, we may content ourselves with having

established the fact, that we do possess and exercise a faculty of pure

à priori cognition; and, secondly, with having pointed out the proper

tests of such cognition, namely, universality and necessity.

Not only in judgements, however, but even in conceptions, is an à

priori origin manifest. For example, if we take away by degrees from

our conceptions of a body all that can be referred to mere sensuous

experience—colour, hardness or softness, weight, even

impenetrability—the body will then vanish; but the space which it

occupied still remains, and this it is utterly impossible to annihilate

in thought. Again, if we take away, in like manner, from our empirical

conception of any object, corporeal or incorporeal, all properties

which mere experience has taught us to connect with it, still we cannot

think away those through which we cogitate it as substance, or adhering

to substance, although our conception of substance is more determined

than that of an object. Compelled, therefore, by that necessity with

which the conception of substance forces itself upon us, we must

confess that it has its seat in our faculty of cognition à priori.

III. Philosophy stands in need of a Science which shall Determine the

Possibility, Principles, and Extent of Human Knowledge “à priori”

Of far more importance than all that has been above said, is the

consideration that certain of our cognitions rise completely above the

sphere of all possible experience, and by means of conceptions, to

which there exists in the whole extent of experience no corresponding

object, seem to extend the range of our judgements beyond its bounds.

And just in this transcendental or supersensible sphere, where

experience affords us neither instruction nor guidance, lie the

investigations of reason, which, on account of their importance, we

consider far preferable to, and as having a far more elevated aim than,

all that the understanding can achieve within the sphere of sensuous

phenomena. So high a value do we set upon these investigations, that

even at the risk of error, we persist in following them out, and permit

neither doubt nor disregard nor indifference to restrain us from the

pursuit. These unavoidable problems of mere pure reason are God,

freedom (of will), and immortality. The science which, with all its

preliminaries, has for its especial object the solution of these

problems is named metaphysics—a science which is at the very outset

dogmatical, that is, it confidently takes upon itself the execution of

this task without any previous investigation of the ability or

inability of reason for such an undertaking.

Now the safe ground of experience being thus abandoned, it seems

nevertheless natural that we should hesitate to erect a building with

the cognitions we possess, without knowing whence they come, and on the

strength of principles, the origin of which is undiscovered. Instead of

thus trying to build without a foundation, it is rather to be expected

that we should long ago have put the question, how the understanding

can arrive at these à priori cognitions, and what is the extent,

validity, and worth which they may possess? We say, “This is natural

enough,” meaning by the word natural, that which is consistent with a

just and reasonable way of thinking; but if we understand by the term,

that which usually happens, nothing indeed could be more natural and

more comprehensible than that this investigation should be left long

unattempted. For one part of our pure knowledge, the science of

mathematics, has been long firmly established, and thus leads us to

form flattering expectations with regard to others, though these may be

of quite a different nature. Besides, when we get beyond the bounds of

experience, we are of course safe from opposition in that quarter; and

the charm of widening the range of our knowledge is so great that,

unless we are brought to a standstill by some evident contradiction, we

hurry on undoubtingly in our course. This, however, may be avoided, if

we are sufficiently cautious in the construction of our fictions, which

are not the less fictions on that account.

Mathematical science affords us a brilliant example, how far,

independently of all experience, we may carry our à priori knowledge.

It is true that the mathematician occupies himself with objects and

cognitions only in so far as they can be represented by means of

intuition. But this circumstance is easily overlooked, because the said

intuition can itself be given à priori, and therefore is hardly to be

distinguished from a mere pure conception. Deceived by such a proof of

the power of reason, we can perceive no limits to the extension of our

knowledge. The light dove cleaving in free flight the thin air, whose

resistance it feels, might imagine that her movements would be far more

free and rapid in airless space. Just in the same way did Plato,

abandoning the world of sense because of the narrow limits it sets to

the understanding, venture upon the wings of ideas beyond it, into the

void space of pure intellect. He did not reflect that he made no real

progress by all his efforts; for he met with no resistance which might

serve him for a support, as it were, whereon to rest, and on which he

might apply his powers, in order to let the intellect acquire momentum

for its progress. It is, indeed, the common fate of human reason in

speculation, to finish the imposing edifice of thought as rapidly as

possible, and then for the first time to begin to examine whether the

foundation is a solid one or no. Arrived at this point, all sorts of

excuses are sought after, in order to console us for its want of

stability, or rather, indeed, to enable Us to dispense altogether with

so late and dangerous an investigation. But what frees us during the

process of building from all apprehension or suspicion, and flatters us

into the belief of its solidity, is this. A great part, perhaps the

greatest part, of the business of our reason consists in the

analysation of the conceptions which we already possess of objects. By

this means we gain a multitude of cognitions, which although really

nothing more than elucidations or explanations of that which (though in

a confused manner) was already thought in our conceptions, are, at

least in respect of their form, prized as new introspections; whilst,

so far as regards their matter or content, we have really made no

addition to our conceptions, but only disinvolved them. But as this

process does furnish a real priori knowledge, which has a sure progress

and useful results, reason, deceived by this, slips in, without being

itself aware of it, assertions of a quite different kind; in which, to

given conceptions it adds others, à priori indeed, but entirely foreign

to them, without our knowing how it arrives at these, and, indeed,

without such a question ever suggesting itself. I shall therefore at

once proceed to examine the difference between these two modes of

knowledge.

IV. Of the Difference Between Analytical and Synthetical Judgements.

In all judgements wherein the relation of a subject to the predicate is

cogitated (I mention affirmative judgements only here; the application

to negative will be very easy), this relation is possible in two

different ways. Either the predicate B belongs to the subject A, as

somewhat which is contained (though covertly) in the conception A; or

the predicate B lies completely out of the conception A, although it

stands in connection with it. In the first instance, I term the

judgement analytical, in the second, synthetical. Analytical judgements

(affirmative) are therefore those in which the connection of the

predicate with the subject is cogitated through identity; those in

which this connection is cogitated without identity, are called

synthetical judgements. The former may be called explicative, the

latter augmentative judgements; because the former add in the predicate

nothing to the conception of the subject, but only analyse it into its

constituent conceptions, which were thought already in the subject,

although in a confused manner; the latter add to our conceptions of the

subject a predicate which was not contained in it, and which no

analysis could ever have discovered therein. For example, when I say,

“All bodies are extended,” this is an analytical judgement. For I need

not go beyond the conception of body in order to find extension

connected with it, but merely analyse the conception, that is, become

conscious of the manifold properties which I think in that conception,

in order to discover this predicate in it: it is therefore an

analytical judgement. On the other hand, when I say, “All bodies are

heavy,” the predicate is something totally different from that which I

think in the mere conception of a body. By the addition of such a

predicate, therefore, it becomes a synthetical judgement.

Judgements of experience, as such, are always synthetical. For it would

be absurd to think of grounding an analytical judgement on experience,

because in forming such a judgement I need not go out of the sphere of

my conceptions, and therefore recourse to the testimony of experience

is quite unnecessary. That “bodies are extended” is not an empirical

judgement, but a proposition which stands firm à priori. For before

addressing myself to experience, I already have in my conception all

the requisite conditions for the judgement, and I have only to extract

the predicate from the conception, according to the principle of

contradiction, and thereby at the same time become conscious of the

necessity of the judgement, a necessity which I could never learn from

experience. On the other hand, though at first I do not at all include

the predicate of weight in my conception of body in general, that

conception still indicates an object of experience, a part of the

totality of experience, to which I can still add other parts; and this

I do when I recognize by observation that bodies are heavy. I can

cognize beforehand by analysis the conception of body through the

characteristics of extension, impenetrability, shape, etc., all which

are cogitated in this conception. But now I extend my knowledge, and

looking back on experience from which I had derived this conception of

body, I find weight at all times connected with the above

characteristics, and therefore I synthetically add to my conceptions

this as a predicate, and say, “All bodies are heavy.” Thus it is

experience upon which rests the possibility of the synthesis of the

predicate of weight with the conception of body, because both

conceptions, although the one is not contained in the other, still

belong to one another (only contingently, however), as parts of a

whole, namely, of experience, which is itself a synthesis of

intuitions.

But to synthetical judgements à priori, such aid is entirely wanting.

If I go out of and beyond the conception A, in order to recognize

another B as connected with it, what foundation have I to rest on,

whereby to render the synthesis possible? I have here no longer the

advantage of looking out in the sphere of experience for what I want.

Let us take, for example, the proposition, “Everything that happens has

a cause.” In the conception of “something that happens,” I indeed think

an existence which a certain time antecedes, and from this I can derive

analytical judgements. But the conception of a cause lies quite out of

the above conception, and indicates something entirely different from

“that which happens,” and is consequently not contained in that

conception. How then am I able to assert concerning the general

conception—“that which happens”—something entirely different from that

conception, and to recognize the conception of cause although not

contained in it, yet as belonging to it, and even necessarily? what is

here the unknown = X, upon which the understanding rests when it

believes it has found, out of the conception A a foreign predicate B,

which it nevertheless considers to be connected with it? It cannot be

experience, because the principle adduced annexes the two

representations, cause and effect, to the representation existence, not

only with universality, which experience cannot give, but also with the

expression of necessity, therefore completely à priori and from pure

conceptions. Upon such synthetical, that is augmentative propositions,

depends the whole aim of our speculative knowledge à priori; for

although analytical judgements are indeed highly important and

necessary, they are so, only to arrive at that clearness of conceptions

which is requisite for a sure and extended synthesis, and this alone is

a real acquisition.

V. In all Theoretical Sciences of Reason, Synthetical Judgements “à

priori” are contained as Principles.

1. Mathematical judgements are always synthetical. Hitherto this fact,

though incontestably true and very important in its consequences, seems

to have escaped the analysts of the human mind, nay, to be in complete

opposition to all their conjectures. For as it was found that

mathematical conclusions all proceed according to the principle of

contradiction (which the nature of every apodeictic certainty

requires), people became persuaded that the fundamental principles of

the science also were recognized and admitted in the same way. But the

notion is fallacious; for although a synthetical proposition can

certainly be discerned by means of the principle of contradiction, this

is possible only when another synthetical proposition precedes, from

which the latter is deduced, but never of itself.

Before all, be it observed, that proper mathematical propositions are

always judgements à priori, and not empirical, because they carry along

with them the conception of necessity, which cannot be given by

experience. If this be demurred to, it matters not; I will then limit

my assertion to pure mathematics, the very conception of which implies

that it consists of knowledge altogether non-empirical and à priori.

We might, indeed at first suppose that the proposition 7 + 5 = 12 is a

merely analytical proposition, following (according to the principle of

contradiction) from the conception of a sum of seven and five. But if

we regard it more narrowly, we find that our conception of the sum of

seven and five contains nothing more than the uniting of both sums into

one, whereby it cannot at all be cogitated what this single number is

which embraces both. The conception of twelve is by no means obtained

by merely cogitating the union of seven and five; and we may analyse

our conception of such a possible sum as long as we will, still we

shall never discover in it the notion of twelve. We must go beyond

these conceptions, and have recourse to an intuition which corresponds

to one of the two—our five fingers, for example, or like Segner in his

Arithmetic five points, and so by degrees, add the units contained in

the five given in the intuition, to the conception of seven. For I

first take the number 7, and, for the conception of 5 calling in the

aid of the fingers of my hand as objects of intuition, I add the units,

which I before took together to make up the number 5, gradually now by

means of the material image my hand, to the number 7, and by this

process, I at length see the number 12 arise. That 7 should be added to

5, I have certainly cogitated in my conception of a sum = 7 + 5, but

not that this sum was equal to 12. Arithmetical propositions are

therefore always synthetical, of which we may become more clearly

convinced by trying large numbers. For it will thus become quite

evident that, turn and twist our conceptions as we may, it is

impossible, without having recourse to intuition, to arrive at the sum

total or product by means of the mere analysis of our conceptions. Just

as little is any principle of pure geometry analytical. “A straight

line between two points is the shortest,” is a synthetical proposition.

For my conception of straight contains no notion of quantity, but is

merely qualitative. The conception of the shortest is therefore fore

wholly an addition, and by no analysis can it be extracted from our

conception of a straight line. Intuition must therefore here lend its

aid, by means of which, and thus only, our synthesis is possible.

Some few principles preposited by geometricians are, indeed, really

analytical, and depend on the principle of contradiction. They serve,

however, like identical propositions, as links in the chain of method,

not as principles—for example, a = a, the whole is equal to itself, or

(a+b) —> a, the whole is greater than its part. And yet even these

principles themselves, though they derive their validity from pure

conceptions, are only admitted in mathematics because they can be

presented in intuition. What causes us here commonly to believe that

the predicate of such apodeictic judgements is already contained in our

conception, and that the judgement is therefore analytical, is merely

the equivocal nature of the expression. We must join in thought a

certain predicate to a given conception, and this necessity cleaves

already to the conception. But the question is, not what we must join

in thought to the given conception, but what we really think therein,

though only obscurely, and then it becomes manifest that the predicate

pertains to these conceptions, necessarily indeed, yet not as thought

in the conception itself, but by virtue of an intuition, which must be

added to the conception.

2. The science of natural philosophy (physics) contains in itself

synthetical judgements à priori, as principles. I shall adduce two

propositions. For instance, the proposition, “In all changes of the

material world, the quantity of matter remains unchanged”; or, that,

“In all communication of motion, action and reaction must always be

equal.” In both of these, not only is the necessity, and therefore

their origin à priori clear, but also that they are synthetical

propositions. For in the conception of matter, I do not cogitate its

permanency, but merely its presence in space, which it fills. I

therefore really go out of and beyond the conception of matter, in

order to think on to it something à priori, which I did not think in

it. The proposition is therefore not analytical, but synthetical, and

nevertheless conceived à priori; and so it is with regard to the other

propositions of the pure part of natural philosophy.

3. As to metaphysics, even if we look upon it merely as an attempted

science, yet, from the nature of human reason, an indispensable one, we

find that it must contain synthetical propositions à priori. It is not

merely the duty of metaphysics to dissect, and thereby analytically to

illustrate the conceptions which we form à priori of things; but we

seek to widen the range of our à priori knowledge. For this purpose, we

must avail ourselves of such principles as add something to the

original conception—something not identical with, nor contained in it,

and by means of synthetical judgements à priori, leave far behind us

the limits of experience; for example, in the proposition, “the world

must have a beginning,” and such like. Thus metaphysics, according to

the proper aim of the science, consists merely of synthetical

propositions à priori.

VI. The Universal Problem of Pure Reason.

It is extremely advantageous to be able to bring a number of

investigations under the formula of a single problem. For in this

manner, we not only facilitate our own labour, inasmuch as we define it

clearly to ourselves, but also render it more easy for others to decide

whether we have done justice to our undertaking. The proper problem of

pure reason, then, is contained in the question: “How are synthetical

judgements à priori possible?”

That metaphysical science has hitherto remained in so vacillating a

state of uncertainty and contradiction, is only to be attributed to the

fact that this great problem, and perhaps even the difference between

analytical and synthetical judgements, did not sooner suggest itself to

philosophers. Upon the solution of this problem, or upon sufficient

proof of the impossibility of synthetical knowledge à priori, depends

the existence or downfall of the science of metaphysics. Among

philosophers, David Hume came the nearest of all to this problem; yet

it never acquired in his mind sufficient precision, nor did he regard

the question in its universality. On the contrary, he stopped short at

the synthetical proposition of the connection of an effect with its

cause (principium causalitatis), insisting that such proposition à

priori was impossible. According to his conclusions, then, all that we

term metaphysical science is a mere delusion, arising from the fancied

insight of reason into that which is in truth borrowed from experience,

and to which habit has given the appearance of necessity. Against this

assertion, destructive to all pure philosophy, he would have been

guarded, had he had our problem before his eyes in its universality.

For he would then have perceived that, according to his own argument,

there likewise could not be any pure mathematical science, which

assuredly cannot exist without synthetical propositions à priori—an

absurdity from which his good understanding must have saved him.

In the solution of the above problem is at the same time comprehended

the possibility of the use of pure reason in the foundation and

construction of all sciences which contain theoretical knowledge à

priori of objects, that is to say, the answer to the following

questions:

How is pure mathematical science possible?

How is pure natural science possible?

Respecting these sciences, as they do certainly exist, it may with

propriety be asked, how they are possible?—for that they must be

possible is shown by the fact of their really existing.[9] But as to

metaphysics, the miserable progress it has hitherto made, and the fact

that of no one system yet brought forward, far as regards its true aim,

can it be said that this science really exists, leaves any one at

liberty to doubt with reason the very possibility of its existence.

[9] As to the existence of pure natural science, or physics, perhaps

many may still express doubts. But we have only to look at the

different propositions which are commonly treated of at the

commencement of proper (empirical) physical science—those, for

example, relating to the permanence of the same quantity of matter,

the vis inertiae, the equality of action and reaction, etc.—to be soon

convinced that they form a science of pure physics (physica pura, or

rationalis), which well deserves to be separately exposed as a special

science, in its whole extent, whether that be great or confined.

Yet, in a certain sense, this kind of knowledge must unquestionably be

looked upon as given; in other words, metaphysics must be considered as

really existing, if not as a science, nevertheless as a natural

disposition of the human mind (metaphysica naturalis). For human

reason, without any instigations imputable to the mere vanity of great

knowledge, unceasingly progresses, urged on by its own feeling of need,

towards such questions as cannot be answered by any empirical

application of reason, or principles derived therefrom; and so there

has ever really existed in every man some system of metaphysics. It

will always exist, so soon as reason awakes to the exercise of its

power of speculation. And now the question arises: “How is metaphysics,

as a natural disposition, possible?” In other words, how, from the

nature of universal human reason, do those questions arise which pure

reason proposes to itself, and which it is impelled by its own feeling

of need to answer as well as it can?

But as in all the attempts hitherto made to answer the questions which

reason is prompted by its very nature to propose to itself, for

example, whether the world had a beginning, or has existed from

eternity, it has always met with unavoidable contradictions, we must

not rest satisfied with the mere natural disposition of the mind to

metaphysics, that is, with the existence of the faculty of pure reason,

whence, indeed, some sort of metaphysical system always arises; but it

must be possible to arrive at certainty in regard to the question

whether we know or do not know the things of which metaphysics treats.

We must be able to arrive at a decision on the subjects of its

questions, or on the ability or inability of reason to form any

judgement respecting them; and therefore either to extend with

confidence the bounds of our pure reason, or to set strictly defined

and safe limits to its action. This last question, which arises out of

the above universal problem, would properly run thus: “How is

metaphysics possible as a science?”

Thus, the critique of reason leads at last, naturally and necessarily,

to science; and, on the other hand, the dogmatical use of reason

without criticism leads to groundless assertions, against which others

equally specious can always be set, thus ending unavoidably in

scepticism.

Besides, this science cannot be of great and formidable prolixity,

because it has not to do with objects of reason, the variety of which

is inexhaustible, but merely with Reason herself and her problems;

problems which arise out of her own bosom, and are not proposed to her

by the nature of outward things, but by her own nature. And when once

Reason has previously become able completely to understand her own

power in regard to objects which she meets with in experience, it will

be easy to determine securely the extent and limits of her attempted

application to objects beyond the confines of experience.

We may and must, therefore, regard the attempts hitherto made to

establish metaphysical science dogmatically as non-existent. For what

of analysis, that is, mere dissection of conceptions, is contained in

one or other, is not the aim of, but only a preparation for metaphysics

proper, which has for its object the extension, by means of synthesis,

of our à priori knowledge. And for this purpose, mere analysis is of

course useless, because it only shows what is contained in these

conceptions, but not how we arrive, à priori, at them; and this it is

her duty to show, in order to be able afterwards to determine their

valid use in regard to all objects of experience, to all knowledge in

general. But little self-denial, indeed, is needed to give up these

pretensions, seeing the undeniable, and in the dogmatic mode of

procedure, inevitable contradictions of Reason with herself, have long

since ruined the reputation of every system of metaphysics that has

appeared up to this time. It will require more firmness to remain

undeterred by difficulty from within, and opposition from without, from

endeavouring, by a method quite opposed to all those hitherto followed,

to further the growth and fruitfulness of a science indispensable to

human reason—a science from which every branch it has borne may be cut

away, but whose roots remain indestructible.

VII. Idea and Division of a Particular Science, under the Name of a

Critique of Pure Reason.

From all that has been said, there results the idea of a particular

science, which may be called the Critique of Pure Reason. For reason is

the faculty which furnishes us with the principles of knowledge à

priori. Hence, pure reason is the faculty which contains the principles

of cognizing anything absolutely à priori. An organon of pure reason

would be a compendium of those principles according to which alone all

pure cognitions à priori can be obtained. The completely extended

application of such an organon would afford us a system of pure reason.

As this, however, is demanding a great deal, and it is yet doubtful

whether any extension of our knowledge be here possible, or, if so, in

what cases; we can regard a science of the mere criticism of pure

reason, its sources and limits, as the propædeutic to a system of pure

reason. Such a science must not be called a doctrine, but only a

critique of pure reason; and its use, in regard to speculation, would

be only negative, not to enlarge the bounds of, but to purify, our

reason, and to shield it against error—which alone is no little gain. I

apply the term transcendental to all knowledge which is not so much

occupied with objects as with the mode of our cognition of these

objects, so far as this mode of cognition is possible à priori. A

system of such conceptions would be called transcendental philosophy.

But this, again, is still beyond the bounds of our present essay. For

as such a science must contain a complete exposition not only of our

synthetical à priori, but of our analytical à priori knowledge, it is

of too wide a range for our present purpose, because we do not require

to carry our analysis any farther than is necessary to understand, in

their full extent, the principles of synthesis à priori, with which

alone we have to do. This investigation, which we cannot properly call

a doctrine, but only a transcendental critique, because it aims not at

the enlargement, but at the correction and guidance, of our knowledge,

and is to serve as a touchstone of the worth or worthlessness of all

knowledge à priori, is the sole object of our present essay. Such a

critique is consequently, as far as possible, a preparation for an

organon; and if this new organon should be found to fail, at least for

a canon of pure reason, according to which the complete system of the

philosophy of pure reason, whether it extend or limit the bounds of

that reason, might one day be set forth both analytically and

synthetically. For that this is possible, nay, that such a system is

not of so great extent as to preclude the hope of its ever being

completed, is evident. For we have not here to do with the nature of

outward objects, which is infinite, but solely with the mind, which

judges of the nature of objects, and, again, with the mind only in

respect of its cognition à priori. And the object of our

investigations, as it is not to be sought without, but, altogether

within, ourselves, cannot remain concealed, and in all probability is

limited enough to be completely surveyed and fairly estimated,

according to its worth or worthlessness. Still less let the reader here

expect a critique of books and systems of pure reason; our present

object is exclusively a critique of the faculty of pure reason itself.

Only when we make this critique our foundation, do we possess a pure

touchstone for estimating the philosophical value of ancient and modern

writings on this subject; and without this criterion, the incompetent

historian or judge decides upon and corrects the groundless assertions

of others with his own, which have themselves just as little

foundation.

Transcendental philosophy is the idea of a science, for which the

Critique of Pure Reason must sketch the whole plan architectonically,

that is, from principles, with a full guarantee for the validity and

stability of all the parts which enter into the building. It is the

system of all the principles of pure reason. If this Critique itself

does not assume the title of transcendental philosophy, it is only

because, to be a complete system, it ought to contain a full analysis

of all human knowledge à priori. Our critique must, indeed, lay before

us a complete enumeration of all the radical conceptions which

constitute the said pure knowledge. But from the complete analysis of

these conceptions themselves, as also from a complete investigation of

those derived from them, it abstains with reason; partly because it

would be deviating from the end in view to occupy itself with this

analysis, since this process is not attended with the difficulty and

insecurity to be found in the synthesis, to which our critique is

entirely devoted, and partly because it would be inconsistent with the

unity of our plan to burden this essay with the vindication of the

completeness of such an analysis and deduction, with which, after all,

we have at present nothing to do. This completeness of the analysis of

these radical conceptions, as well as of the deduction from the

conceptions à priori which may be given by the analysis, we can,

however, easily attain, provided only that we are in possession of all

these radical conceptions, which are to serve as principles of the

synthesis, and that in respect of this main purpose nothing is wanting.

To the Critique of Pure Reason, therefore, belongs all that constitutes

transcendental philosophy; and it is the complete idea of

transcendental philosophy, but still not the science itself; because it

only proceeds so far with the analysis as is necessary to the power of

judging completely of our synthetical knowledge à priori.

The principal thing we must attend to, in the division of the parts of

a science like this, is that no conceptions must enter it which contain

aught empirical; in other words, that the knowledge à priori must be

completely pure. Hence, although the highest principles and fundamental

conceptions of morality are certainly cognitions à priori, yet they do

not belong to transcendental philosophy; because, though they certainly

do not lay the conceptions of pain, pleasure, desires, inclinations,

etc. (which are all of empirical origin), at the foundation of its

precepts, yet still into the conception of duty—as an obstacle to be

overcome, or as an incitement which should not be made into a

motive—these empirical conceptions must necessarily enter, in the

construction of a system of pure morality. Transcendental philosophy is

consequently a philosophy of the pure and merely speculative reason.

For all that is practical, so far as it contains motives, relates to

feelings, and these belong to empirical sources of cognition.

If we wish to divide this science from the universal point of view of a

science in general, it ought to comprehend, first, a Doctrine of the

Elements, and, secondly, a Doctrine of the Method of pure reason. Each

of these main divisions will have its subdivisions, the separate

reasons for which we cannot here particularize. Only so much seems

necessary, by way of introduction of premonition, that there are two

sources of human knowledge (which probably spring from a common, but to

us unknown root), namely, sense and understanding. By the former,

objects are given to us; by the latter, thought. So far as the faculty

of sense may contain representations à priori, which form the

conditions under which objects are given, in so far it belongs to

transcendental philosophy. The transcendental doctrine of sense must

form the first part of our science of elements, because the conditions

under which alone the objects of human knowledge are given must precede

those under which they are thought.

I. TRANSCENDENTAL DOCTRINE OF ELEMENTS.

FIRST PART. TRANSCENDENTAL ÆSTHETIC.

§ I. Introductory.

In whatsoever mode, or by whatsoever means, our knowledge may relate to

objects, it is at least quite clear that the only manner in which it

immediately relates to them is by means of an intuition. To this as the

indispensable groundwork, all thought points. But an intuition can take

place only in so far as the object is given to us. This, again, is only

possible, to man at least, on condition that the object affect the mind

in a certain manner. The capacity for receiving representations

(receptivity) through the mode in which we are affected by objects,

objects, is called sensibility. By means of sensibility, therefore,

objects are given to us, and it alone furnishes us with intuitions; by

the understanding they are thought, and from it arise conceptions. But

an thought must directly, or indirectly, by means of certain signs,

relate ultimately to intuitions; consequently, with us, to sensibility,

because in no other way can an object be given to us.

The effect of an object upon the faculty of representation, so far as

we are affected by the said object, is sensation. That sort of

intuition which relates to an object by means of sensation is called an

empirical intuition. The undetermined object of an empirical intuition

is called phenomenon. That which in the phenomenon corresponds to the

sensation, I term its matter; but that which effects that the content

of the phenomenon can be arranged under certain relations, I call its

form. But that in which our sensations are merely arranged, and by

which they are susceptible of assuming a certain form, cannot be itself

sensation. It is, then, the matter of all phenomena that is given to us

à posteriori; the form must lie ready à priori for them in the mind,

and consequently can be regarded separately from all sensation.

I call all representations pure, in the transcendental meaning of the

word, wherein nothing is met with that belongs to sensation. And

accordingly we find existing in the mind à priori, the pure form of

sensuous intuitions in general, in which all the manifold content of

the phenomenal world is arranged and viewed under certain relations.

This pure form of sensibility I shall call pure intuition. Thus, if I

take away from our representation of a body all that the understanding

thinks as belonging to it, as substance, force, divisibility, etc., and

also whatever belongs to sensation, as impenetrability, hardness,

colour, etc.; yet there is still something left us from this empirical

intuition, namely, extension and shape. These belong to pure intuition,

which exists à priori in the mind, as a mere form of sensibility, and

without any real object of the senses or any sensation.

The science of all the principles of sensibility à priori, I call

transcendental æsthetic.[10] There must, then, be such a science

forming the first part of the transcendental doctrine of elements, in

contradistinction to that part which contains the principles of pure

thought, and which is called transcendental logic.

[10] The Germans are the only people who at present use this word to

indicate what others call the critique of taste. At the foundation of

this term lies the disappointed hope, which the eminent analyst,

Baumgarten, conceived, of subjecting the criticism of the beautiful to

principles of reason, and so of elevating its rules into a science.

But his endeavours were vain. For the said rules or criteria are, in

respect to their chief sources, merely empirical, consequently never

can serve as determinate laws à priori, by which our judgement in

matters of taste is to be directed. It is rather our judgement which

forms the proper test as to the correctness of the principles. On this

account it is advisable to give up the use of the term as designating

the critique of taste, and to apply it solely to that doctrine, which

is true science—the science of the laws of sensibility—and thus come

nearer to the language and the sense of the ancients in their

well-known division of the objects of cognition into aiotheta kai

noeta, or to share it with speculative philosophy, and employ it

partly in a transcendental, partly in a psychological signification.

In the science of transcendental æsthetic accordingly, we shall first

isolate sensibility or the sensuous faculty, by separating from it all

that is annexed to its perceptions by the conceptions of understanding,

so that nothing be left but empirical intuition. In the next place we

shall take away from this intuition all that belongs to sensation, so

that nothing may remain but pure intuition, and the mere form of

phenomena, which is all that the sensibility can afford à priori. From

this investigation it will be found that there are two pure forms of

sensuous intuition, as principles of knowledge à priori, namely, space

and time. To the consideration of these we shall now proceed.

SECTION I. Of Space.

§ 2. Metaphysical Exposition of this Conception.

By means of the external sense (a property of the mind), we represent

to ourselves objects as without us, and these all in space. Herein

alone are their shape, dimensions, and relations to each other

determined or determinable. The internal sense, by means of which the

mind contemplates itself or its internal state, gives, indeed, no

intuition of the soul as an object; yet there is nevertheless a

determinate form, under which alone the contemplation of our internal

state is possible, so that all which relates to the inward

determinations of the mind is represented in relations of time. Of time

we cannot have any external intuition, any more than we can have an

internal intuition of space. What then are time and space? Are they

real existences? Or, are they merely relations or determinations of

things, such, however, as would equally belong to these things in

themselves, though they should never become objects of intuition; or,

are they such as belong only to the form of intuition, and consequently

to the subjective constitution of the mind, without which these

predicates of time and space could not be attached to any object? In

order to become informed on these points, we shall first give an

exposition of the conception of space. By exposition, I mean the clear,

though not detailed, representation of that which belongs to a

conception; and an exposition is metaphysical when it contains that

which represents the conception as given à priori.

1. Space is not a conception which has been derived from outward

experiences. For, in order that certain sensations may relate to

something without me (that is, to something which occupies a different

part of space from that in which I am); in like manner, in order that I

may represent them not merely as without, of, and near to each other,

but also in separate places, the representation of space must already

exist as a foundation. Consequently, the representation of space cannot

be borrowed from the relations of external phenomena through

experience; but, on the contrary, this external experience is itself

only possible through the said antecedent representation.

2. Space then is a necessary representation à priori, which serves for

the foundation of all external intuitions. We never can imagine or make

a representation to ourselves of the non-existence of space, though we

may easily enough think that no objects are found in it. It must,

therefore, be considered as the condition of the possibility of

phenomena, and by no means as a determination dependent on them, and is

a representation à priori, which necessarily supplies the basis for

external phenomena.

3. Space is no discursive, or as we say, general conception of the

relations of things, but a pure intuition. For, in the first place, we

can only represent to ourselves one space, and, when we talk of divers

spaces, we mean only parts of one and the same space. Moreover, these

parts cannot antecede this one all-embracing space, as the component

parts from which the aggregate can be made up, but can be cogitated

only as existing in it. Space is essentially one, and multiplicity in

it, consequently the general notion of spaces, of this or that space,

depends solely upon limitations. Hence it follows that an à priori

intuition (which is not empirical) lies at the root of all our

conceptions of space. Thus, moreover, the principles of geometry—for

example, that “in a triangle, two sides together are greater than the

third,” are never deduced from general conceptions of line and

triangle, but from intuition, and this à priori, with apodeictic

certainty.

4. Space is represented as an infinite given quantity. Now every

conception must indeed be considered as a representation which is

contained in an infinite multitude of different possible

representations, which, therefore, comprises these under itself; but no

conception, as such, can be so conceived, as if it contained within

itself an infinite multitude of representations. Nevertheless, space is

so conceived of, for all parts of space are equally capable of being

produced to infinity. Consequently, the original representation of

space is an intuition à priori, and not a conception.

§ 3. Transcendental Exposition of the Conception of Space.

By a transcendental exposition, I mean the explanation of a conception,

as a principle, whence can be discerned the possibility of other

synthetical à priori cognitions. For this purpose, it is requisite,

firstly, that such cognitions do really flow from the given conception;

and, secondly, that the said cognitions are only possible under the

presupposition of a given mode of explaining this conception.

Geometry is a science which determines the properties of space

synthetically, and yet à priori. What, then, must be our representation

of space, in order that such a cognition of it may be possible? It must

be originally intuition, for from a mere conception, no propositions

can be deduced which go out beyond the conception, and yet this happens

in geometry. (Introd. V.) But this intuition must be found in the mind

à priori, that is, before any perception of objects, consequently must

be pure, not empirical, intuition. For geometrical principles are

always apodeictic, that is, united with the consciousness of their

necessity, as: “Space has only three dimensions.” But propositions of

this kind cannot be empirical judgements, nor conclusions from them.

(Introd. II.) Now, how can an external intuition anterior to objects

themselves, and in which our conception of objects can be determined à

priori, exist in the human mind? Obviously not otherwise than in so far

as it has its seat in the subject only, as the formal capacity of the

subject’s being affected by objects, and thereby of obtaining immediate

representation, that is, intuition; consequently, only as the form of

the external sense in general.

Thus it is only by means of our explanation that the possibility of

geometry, as a synthetical science à priori, becomes comprehensible.

Every mode of explanation which does not show us this possibility,

although in appearance it may be similar to ours, can with the utmost

certainty be distinguished from it by these marks.

§ 4. Conclusions from the foregoing Conceptions.

(a) Space does not represent any property of objects as things in

themselves, nor does it represent them in their relations to each

other; in other words, space does not represent to us any determination

of objects such as attaches to the objects themselves, and would

remain, even though all subjective conditions of the intuition were

abstracted. For neither absolute nor relative determinations of objects

can be intuited prior to the existence of the things to which they

belong, and therefore not à priori.

(b) Space is nothing else than the form of all phenomena of the

external sense, that is, the subjective condition of the sensibility,

under which alone external intuition is possible. Now, because the

receptivity or capacity of the subject to be affected by objects

necessarily antecedes all intuitions of these objects, it is easily

understood how the form of all phenomena can be given in the mind

previous to all actual perceptions, therefore à priori, and how it, as

a pure intuition, in which all objects must be determined, can contain

principles of the relations of these objects prior to all experience.

It is therefore from the human point of view only that we can speak of

space, extended objects, etc. If we depart from the subjective

condition, under which alone we can obtain external intuition, or, in

other words, by means of which we are affected by objects, the

representation of space has no meaning whatsoever. This predicate is

only applicable to things in so far as they appear to us, that is, are

objects of sensibility. The constant form of this receptivity, which we

call sensibility, is a necessary condition of all relations in which

objects can be intuited as existing without us, and when abstraction of

these objects is made, is a pure intuition, to which we give the name

of space. It is clear that we cannot make the special conditions of

sensibility into conditions of the possibility of things, but only of

the possibility of their existence as far as they are phenomena. And so

we may correctly say that space contains all which can appear to us

externally, but not all things considered as things in themselves, be

they intuited or not, or by whatsoever subject one will. As to the

intuitions of other thinking beings, we cannot judge whether they are

or are not bound by the same conditions which limit our own intuition,

and which for us are universally valid. If we join the limitation of a

judgement to the conception of the subject, then the judgement will

possess unconditioned validity. For example, the proposition, “All

objects are beside each other in space,” is valid only under the

limitation that these things are taken as objects of our sensuous

intuition. But if I join the condition to the conception and say, “All

things, as external phenomena, are beside each other in space,” then

the rule is valid universally, and without any limitation. Our

expositions, consequently, teach the reality (i.e., the objective

validity) of space in regard of all which can be presented to us

externally as object, and at the same time also the ideality of space

in regard to objects when they are considered by means of reason as

things in themselves, that is, without reference to the constitution of

our sensibility. We maintain, therefore, the empirical reality of space

in regard to all possible external experience, although we must admit

its transcendental ideality; in other words, that it is nothing, so

soon as we withdraw the condition upon which the possibility of all

experience depends and look upon space as something that belongs to

things in themselves.

But, with the exception of space, there is no representation,

subjective and referring to something external to us, which could be

called objective à priori. For there are no other subjective

representations from which we can deduce synthetical propositions à

priori, as we can from the intuition of space. (See § 3.) Therefore, to

speak accurately, no ideality whatever belongs to these, although they

agree in this respect with the representation of space, that they

belong merely to the subjective nature of the mode of sensuous

perception; such a mode, for example, as that of sight, of hearing, and

of feeling, by means of the sensations of colour, sound, and heat, but

which, because they are only sensations and not intuitions, do not of

themselves give us the cognition of any object, least of all, an à

priori cognition. My purpose, in the above remark, is merely this: to

guard any one against illustrating the asserted ideality of space by

examples quite insufficient, for example, by colour, taste, etc.; for

these must be contemplated not as properties of things, but only as

changes in the subject, changes which may be different in different

men. For, in such a case, that which is originally a mere phenomenon, a

rose, for example, is taken by the empirical understanding for a thing

in itself, though to every different eye, in respect of its colour, it

may appear different. On the contrary, the transcendental conception of

phenomena in space is a critical admonition, that, in general, nothing

which is intuited in space is a thing in itself, and that space is not

a form which belongs as a property to things; but that objects are

quite unknown to us in themselves, and what we call outward objects,

are nothing else but mere representations of our sensibility, whose

form is space, but whose real correlate, the thing in itself, is not

known by means of these representations, nor ever can be, but

respecting which, in experience, no inquiry is ever made.

SECTION II. Of Time.

§ 5. Metaphysical Exposition of this Conception.

1. Time is not an empirical conception. For neither coexistence nor

succession would be perceived by us, if the representation of time did

not exist as a foundation à priori. Without this presupposition we

could not represent to ourselves that things exist together at one and

the same time, or at different times, that is, contemporaneously, or in

succession.

2. Time is a necessary representation, lying at the foundation of all

our intuitions. With regard to phenomena in general, we cannot think

away time from them, and represent them to ourselves as out of and

unconnected with time, but we can quite well represent to ourselves

time void of phenomena. Time is therefore given à priori. In it alone

is all reality of phenomena possible. These may all be annihilated in

thought, but time itself, as the universal condition of their

possibility, cannot be so annulled.

3. On this necessity à priori is also founded the possibility of

apodeictic principles of the relations of time, or axioms of time in

general, such as: “Time has only one dimension,” “Different times are

not coexistent but successive” (as different spaces are not successive

but coexistent). These principles cannot be derived from experience,

for it would give neither strict universality, nor apodeictic

certainty. We should only be able to say, “so common experience teaches

us,” but not “it must be so.” They are valid as rules, through which,

in general, experience is possible; and they instruct us respecting

experience, and not by means of it.

4. Time is not a discursive, or as it is called, general conception,

but a pure form of the sensuous intuition. Different times are merely

parts of one and the same time. But the representation which can only

be given by a single object is an intuition. Besides, the proposition

that different times cannot be coexistent could not be derived from a

general conception. For this proposition is synthetical, and therefore

cannot spring out of conceptions alone. It is therefore contained

immediately in the intuition and representation of time.

5. The infinity of time signifies nothing more than that every

determined quantity of time is possible only through limitations of one

time lying at the foundation. Consequently, the original

representation, time, must be given as unlimited. But as the

determinate representation of the parts of time and of every quantity

of an object can only be obtained by limitation, the complete

representation of time must not be furnished by means of conceptions,

for these contain only partial representations. Conceptions, on the

contrary, must have immediate intuition for their basis.

§ 6 Transcendental Exposition of the Conception of Time.

I may here refer to what is said above (§ 5, 3), where, for or sake of

brevity, I have placed under the head of metaphysical exposition, that

which is properly transcendental. Here I shall add that the conception

of change, and with it the conception of motion, as change of place, is

possible only through and in the representation of time; that if this

representation were not an intuition (internal) à priori, no

conception, of whatever kind, could render comprehensible the

possibility of change, in other words, of a conjunction of

contradictorily opposed predicates in one and the same object, for

example, the presence of a thing in a place and the non-presence of the

same thing in the same place. It is only in time that it is possible to

meet with two contradictorily opposed determinations in one thing, that

is, after each other. Thus our conception of time explains the

possibility of so much synthetical knowledge à priori, as is exhibited

in the general doctrine of motion, which is not a little fruitful.

§ 7. Conclusions from the above Conceptions.

(a) Time is not something which subsists of itself, or which inheres in

things as an objective determination, and therefore remains, when

abstraction is made of the subjective conditions of the intuition of

things. For in the former case, it would be something real, yet without

presenting to any power of perception any real object. In the latter

case, as an order or determination inherent in things themselves, it

could not be antecedent to things, as their condition, nor discerned or

intuited by means of synthetical propositions à priori. But all this is

quite possible when we regard time as merely the subjective condition

under which all our intuitions take place. For in that case, this form

of the inward intuition can be represented prior to the objects, and

consequently à priori.

(b) Time is nothing else than the form of the internal sense, that is,

of the intuitions of self and of our internal state. For time cannot be

any determination of outward phenomena. It has to do neither with shape

nor position; on the contrary, it determines the relation of

representations in our internal state. And precisely because this

internal intuition presents to us no shape or form, we endeavour to

supply this want by analogies, and represent the course of time by a

line progressing to infinity, the content of which constitutes a series

which is only of one dimension; and we conclude from the properties of

this line as to all the properties of time, with this single exception,

that the parts of the line are coexistent, whilst those of time are

successive. From this it is clear also that the representation of time

is itself an intuition, because all its relations can be expressed in

an external intuition.

(c) Time is the formal condition à priori of all phenomena whatsoever.

Space, as the pure form of external intuition, is limited as a

condition à priori to external phenomena alone. On the other hand,

because all representations, whether they have or have not external

things for their objects, still in themselves, as determinations of the

mind, belong to our internal state; and because this internal state is

subject to the formal condition of the internal intuition, that is, to

time—time is a condition à priori of all phenomena whatsoever—the

immediate condition of all internal, and thereby the mediate condition

of all external phenomena. If I can say à priori, “All outward

phenomena are in space, and determined à priori according to the

relations of space,” I can also, from the principle of the internal

sense, affirm universally, “All phenomena in general, that is, all

objects of the senses, are in time and stand necessarily in relations

of time.”

If we abstract our internal intuition of ourselves and all external

intuitions, possible only by virtue of this internal intuition and

presented to us by our faculty of representation, and consequently take

objects as they are in themselves, then time is nothing. It is only of

objective validity in regard to phenomena, because these are things

which we regard as objects of our senses. It no longer objective we,

make abstraction of the sensuousness of our intuition, in other words,

of that mode of representation which is peculiar to us, and speak of

things in general. Time is therefore merely a subjective condition of

our (human) intuition (which is always sensuous, that is, so far as we

are affected by objects), and in itself, independently of the mind or

subject, is nothing. Nevertheless, in respect of all phenomena,

consequently of all things which come within the sphere of our

experience, it is necessarily objective. We cannot say, “All things are

in time,” because in this conception of things in general, we abstract

and make no mention of any sort of intuition of things. But this is the

proper condition under which time belongs to our representation of

objects. If we add the condition to the conception, and say, “All

things, as phenomena, that is, objects of sensuous intuition, are in

time,” then the proposition has its sound objective validity and

universality à priori.

What we have now set forth teaches, therefore, the empirical reality of

time; that is, its objective validity in reference to all objects which

can ever be presented to our senses. And as our intuition is always

sensuous, no object ever can be presented to us in experience, which

does not come under the conditions of time. On the other hand, we deny

to time all claim to absolute reality; that is, we deny that it,

without having regard to the form of our sensuous intuition, absolutely

inheres in things as a condition or property. Such properties as belong

to objects as things in themselves never can be presented to us through

the medium of the senses. Herein consists, therefore, the

transcendental ideality of time, according to which, if we abstract the

subjective conditions of sensuous intuition, it is nothing, and cannot

be reckoned as subsisting or inhering in objects as things in

themselves, independently of its relation to our intuition. This

ideality, like that of space, is not to be proved or illustrated by

fallacious analogies with sensations, for this reason—that in such

arguments or illustrations, we make the presupposition that the

phenomenon, in which such and such predicates inhere, has objective

reality, while in this case we can only find such an objective reality

as is itself empirical, that is, regards the object as a mere

phenomenon. In reference to this subject, see the remark in Section I

(§ 4)

§ 8. Elucidation.

Against this theory, which grants empirical reality to time, but denies

to it absolute and transcendental reality, I have heard from

intelligent men an objection so unanimously urged that I conclude that

it must naturally present itself to every reader to whom these

considerations are novel. It runs thus: “Changes are real” (this the

continual change in our own representations demonstrates, even though

the existence of all external phenomena, together with their changes,

is denied). Now, changes are only possible in time, and therefore time

must be something real. But there is no difficulty in answering this. I

grant the whole argument. Time, no doubt, is something real, that is,

it is the real form of our internal intuition. It therefore has

subjective reality, in reference to our internal experience, that is, I

have really the representation of time and of my determinations

therein. Time, therefore, is not to be regarded as an object, but as

the mode of representation of myself as an object. But if I could

intuite myself, or be intuited by another being, without this condition

of sensibility, then those very determinations which we now represent

to ourselves as changes, would present to us a knowledge in which the

representation of time, and consequently of change, would not appear.

The empirical reality of time, therefore, remains, as the condition of

all our experience. But absolute reality, according to what has been

said above, cannot be granted it. Time is nothing but the form of our

internal intuition.[11] If we take away from it the special condition

of our sensibility, the conception of time also vanishes; and it

inheres not in the objects themselves, but solely in the subject (or

mind) which intuites them.

[11] I can indeed say “my representations follow one another, or are

successive”; but this means only that we are conscious of them as in a

succession, that is, according to the form of the internal sense.

Time, therefore, is not a thing in itself, nor is it any objective

determination pertaining to, or inherent in things.

But the reason why this objection is so unanimously brought against our

doctrine of time, and that too by disputants who cannot start any

intelligible arguments against the doctrine of the ideality of space,

is this—they have no hope of demonstrating apodeictically the absolute

reality of space, because the doctrine of idealism is against them,

according to which the reality of external objects is not capable of

any strict proof. On the other hand, the reality of the object of our

internal sense (that is, myself and my internal state) is clear

immediately through consciousness. The former—external objects in

space—might be a mere delusion, but the latter—the object of my

internal perception—is undeniably real. They do not, however, reflect

that both, without question of their reality as representations, belong

only to the genus phenomenon, which has always two aspects, the one,

the object considered as a thing in itself, without regard to the mode

of intuiting it, and the nature of which remains for this very reason

problematical, the other, the form of our intuition of the object,

which must be sought not in the object as a thing in itself, but in the

subject to which it appears—which form of intuition nevertheless

belongs really and necessarily to the phenomenal object.

Time and space are, therefore, two sources of knowledge, from which, à

priori, various synthetical cognitions can be drawn. Of this we find a

striking example in the cognitions of space and its relations, which

form the foundation of pure mathematics. They are the two pure forms of

all intuitions, and thereby make synthetical propositions à priori

possible. But these sources of knowledge being merely conditions of our

sensibility, do therefore, and as such, strictly determine their own

range and purpose, in that they do not and cannot present objects as

things in themselves, but are applicable to them solely in so far as

they are considered as sensuous phenomena. The sphere of phenomena is

the only sphere of their validity, and if we venture out of this, no

further objective use can be made of them. For the rest, this formal

reality of time and space leaves the validity of our empirical

knowledge unshaken; for our certainty in that respect is equally firm,

whether these forms necessarily inhere in the things themselves, or

only in our intuitions of them. On the other hand, those who maintain

the absolute reality of time and space, whether as essentially

subsisting, or only inhering, as modifications, in things, must find

themselves at utter variance with the principles of experience itself.

For, if they decide for the first view, and make space and time into

substances, this being the side taken by mathematical natural

philosophers, they must admit two self-subsisting nonentities, infinite

and eternal, which exist (yet without there being anything real) for

the purpose of containing in themselves everything that is real. If

they adopt the second view of inherence, which is preferred by some

metaphysical natural philosophers, and regard space and time as

relations (contiguity in space or succession in time), abstracted from

experience, though represented confusedly in this state of separation,

they find themselves in that case necessitated to deny the validity of

mathematical doctrines à priori in reference to real things (for

example, in space)—at all events their apodeictic certainty. For such

certainty cannot be found in an à posteriori proposition; and the

conceptions à priori of space and time are, according to this opinion,

mere creations of the imagination, having their source really in

experience, inasmuch as, out of relations abstracted from experience,

imagination has made up something which contains, indeed, general

statements of these relations, yet of which no application can be made

without the restrictions attached thereto by nature. The former of

these parties gains this advantage, that they keep the sphere of

phenomena free for mathematical science. On the other hand, these very

conditions (space and time) embarrass them greatly, when the

understanding endeavours to pass the limits of that sphere. The latter

has, indeed, this advantage, that the representations of space and time

do not come in their way when they wish to judge of objects, not as

phenomena, but merely in their relation to the understanding. Devoid,

however, of a true and objectively valid à priori intuition, they can

neither furnish any basis for the possibility of mathematical

cognitions à priori, nor bring the propositions of experience into

necessary accordance with those of mathematics. In our theory of the

true nature of these two original forms of the sensibility, both

difficulties are surmounted.

In conclusion, that transcendental æsthetic cannot contain any more

than these two elements—space and time, is sufficiently obvious from

the fact that all other conceptions appertaining to sensibility, even

that of motion, which unites in itself both elements, presuppose

something empirical. Motion, for example, presupposes the perception of

something movable. But space considered in itself contains nothing

movable, consequently motion must be something which is found in space

only through experience—in other words, an empirical datum. In like

manner, transcendental æsthetic cannot number the conception of change

among its data à priori; for time itself does not change, but only

something which is in time. To acquire the conception of change,

therefore, the perception of some existing object and of the succession

of its determinations, in one word, experience, is necessary.

§ 9. General Remarks on Transcendental Æsthetic.

I. In order to prevent any misunderstanding, it will be requisite, in

the first place, to recapitulate, as clearly as possible, what our

opinion is with respect to the fundamental nature of our sensuous

cognition in general. We have intended, then, to say that all our

intuition is nothing but the representation of phenomena; that the

things which we intuite, are not in themselves the same as our

representations of them in intuition, nor are their relations in

themselves so constituted as they appear to us; and that if we take

away the subject, or even only the subjective constitution of our

senses in general, then not only the nature and relations of objects in

space and time, but even space and time themselves disappear; and that

these, as phenomena, cannot exist in themselves, but only in us. What

may be the nature of objects considered as things in themselves and

without reference to the receptivity of our sensibility is quite

unknown to us. We know nothing more than our mode of perceiving them,

which is peculiar to us, and which, though not of necessity pertaining

to every animated being, is so to the whole human race. With this alone

we have to do. Space and time are the pure forms thereof; sensation the

matter. The former alone can we cognize à priori, that is, antecedent

to all actual perception; and for this reason such cognition is called

pure intuition. The latter is that in our cognition which is called

cognition à posteriori, that is, empirical intuition. The former

appertain absolutely and necessarily to our sensibility, of whatsoever

kind our sensations may be; the latter may be of very diversified

character. Supposing that we should carry our empirical intuition even

to the very highest degree of clearness, we should not thereby advance

one step nearer to a knowledge of the constitution of objects as things

in themselves. For we could only, at best, arrive at a complete

cognition of our own mode of intuition, that is of our sensibility, and

this always under the conditions originally attaching to the subject,

namely, the conditions of space and time; while the question: “What are

objects considered as things in themselves?” remains unanswerable even

after the most thorough examination of the phenomenal world.

To say, then, that all our sensibility is nothing but the confused

representation of things containing exclusively that which belongs to

them as things in themselves, and this under an accumulation of

characteristic marks and partial representations which we cannot

distinguish in consciousness, is a falsification of the conception of

sensibility and phenomenization, which renders our whole doctrine

thereof empty and useless. The difference between a confused and a

clear representation is merely logical and has nothing to do with

content. No doubt the conception of right, as employed by a sound

understanding, contains all that the most subtle investigation could

unfold from it, although, in the ordinary practical use of the word, we

are not conscious of the manifold representations comprised in the

conception. But we cannot for this reason assert that the ordinary

conception is a sensuous one, containing a mere phenomenon, for right

cannot appear as a phenomenon; but the conception of it lies in the

understanding, and represents a property (the moral property) of

actions, which belongs to them in themselves. On the other hand, the

representation in intuition of a body contains nothing which could

belong to an object considered as a thing in itself, but merely the

phenomenon or appearance of something, and the mode in which we are

affected by that appearance; and this receptivity of our faculty of

cognition is called sensibility, and remains toto caelo different from

the cognition of an object in itself, even though we should examine the

content of the phenomenon to the very bottom.

It must be admitted that the Leibnitz-Wolfian philosophy has assigned

an entirely erroneous point of view to all investigations into the

nature and origin of our cognitions, inasmuch as it regards the

distinction between the sensuous and the intellectual as merely

logical, whereas it is plainly transcendental, and concerns not merely

the clearness or obscurity, but the content and origin of both. For the

faculty of sensibility not only does not present us with an indistinct

and confused cognition of objects as things in themselves, but, in

fact, gives us no knowledge of these at all. On the contrary, so soon

as we abstract in thought our own subjective nature, the object

represented, with the properties ascribed to it by sensuous intuition,

entirely disappears, because it was only this subjective nature that

determined the form of the object as a phenomenon.

In phenomena, we commonly, indeed, distinguish that which essentially

belongs to the intuition of them, and is valid for the sensuous faculty

of every human being, from that which belongs to the same intuition

accidentally, as valid not for the sensuous faculty in general, but for

a particular state or organization of this or that sense. Accordingly,

we are accustomed to say that the former is a cognition which

represents the object itself, whilst the latter presents only a

particular appearance or phenomenon thereof. This distinction, however,

is only empirical. If we stop here (as is usual), and do not regard the

empirical intuition as itself a mere phenomenon (as we ought to do), in

which nothing that can appertain to a thing in itself is to be found,

our transcendental distinction is lost, and we believe that we cognize

objects as things in themselves, although in the whole range of the

sensuous world, investigate the nature of its objects as profoundly as

we may, we have to do with nothing but phenomena. Thus, we call the

rainbow a mere appearance of phenomenon in a sunny shower, and the

rain, the reality or thing in itself; and this is right enough, if we

understand the latter conception in a merely physical sense, that is,

as that which in universal experience, and under whatever conditions of

sensuous perception, is known in intuition to be so and so determined,

and not otherwise. But if we consider this empirical datum generally,

and inquire, without reference to its accordance with all our senses,

whether there can be discovered in it aught which represents an object

as a thing in itself (the raindrops of course are not such, for they

are, as phenomena, empirical objects), the question of the relation of

the representation to the object is transcendental; and not only are

the raindrops mere phenomena, but even their circular form, nay, the

space itself through which they fall, is nothing in itself, but both

are mere modifications or fundamental dispositions of our sensuous

intuition, whilst the transcendental object remains for us utterly

unknown.

The second important concern of our æsthetic is that it does not obtain

favour merely as a plausible hypothesis, but possess as undoubted a

character of certainty as can be demanded of any theory which is to

serve for an organon. In order fully to convince the reader of this

certainty, we shall select a case which will serve to make its validity

apparent, and also to illustrate what has been said in § 3.

Suppose, then, that space and time are in themselves objective, and

conditions of the—possibility of objects as things in themselves. In

the first place, it is evident that both present us, with very many

apodeictic and synthetic propositions à priori, but especially

space—and for this reason we shall prefer it for investigation at

present. As the propositions of geometry are cognized synthetically à

priori, and with apodeictic certainty, I inquire: Whence do you obtain

propositions of this kind, and on what basis does the understanding

rest, in order to arrive at such absolutely necessary and universally

valid truths?

There is no other way than through intuitions or conceptions, as such;

and these are given either à priori or à posteriori. The latter,

namely, empirical conceptions, together with the empirical intuition on

which they are founded, cannot afford any synthetical proposition,

except such as is itself also empirical, that is, a proposition of

experience. But an empirical proposition cannot possess the qualities

of necessity and absolute universality, which, nevertheless, are the

characteristics of all geometrical propositions. As to the first and

only means to arrive at such cognitions, namely, through mere

conceptions or intuitions à priori, it is quite clear that from mere

conceptions no synthetical cognitions, but only analytical ones, can be

obtained. Take, for example, the proposition: “Two straight lines

cannot enclose a space, and with these alone no figure is possible,”

and try to deduce it from the conception of a straight line and the

number two; or take the proposition: “It is possible to construct a

figure with three straight lines,” and endeavour, in like manner, to

deduce it from the mere conception of a straight line and the number

three. All your endeavours are in vain, and you find yourself forced to

have recourse to intuition, as, in fact, geometry always does. You

therefore give yourself an object in intuition. But of what kind is

this intuition? Is it a pure à priori, or is it an empirical intuition?

If the latter, then neither an universally valid, much less an

apodeictic proposition can arise from it, for experience never can give

us any such proposition. You must, therefore, give yourself an object à

priori in intuition, and upon that ground your synthetical proposition.

Now if there did not exist within you a faculty of intuition à priori;

if this subjective condition were not in respect to its form also the

universal condition à priori under which alone the object of this

external intuition is itself possible; if the object (that is, the

triangle) were something in itself, without relation to you the

subject; how could you affirm that that which lies necessarily in your

subjective conditions in order to construct a triangle, must also

necessarily belong to the triangle in itself? For to your conceptions

of three lines, you could not add anything new (that is, the figure);

which, therefore, must necessarily be found in the object, because the

object is given before your cognition, and not by means of it. If,

therefore, space (and time also) were not a mere form of your

intuition, which contains conditions à priori, under which alone things

can become external objects for you, and without which subjective

conditions the objects are in themselves nothing, you could not

construct any synthetical proposition whatsoever regarding external

objects. It is therefore not merely possible or probable, but

indubitably certain, that space and time, as the necessary conditions

of all our external and internal experience, are merely subjective

conditions of all our intuitions, in relation to which all objects are

therefore mere phenomena, and not things in themselves, presented to us

in this particular manner. And for this reason, in respect to the form

of phenomena, much may be said à priori, whilst of the thing in itself,

which may lie at the foundation of these phenomena, it is impossible to

say anything.

II. In confirmation of this theory of the ideality of the external as

well as internal sense, consequently of all objects of sense, as mere

phenomena, we may especially remark that all in our cognition that

belongs to intuition contains nothing more than mere relations. (The

feelings of pain and pleasure, and the will, which are not cognitions,

are excepted.) The relations, to wit, of place in an intuition

(extension), change of place (motion), and laws according to which this

change is determined (moving forces). That, however, which is present

in this or that place, or any operation going on, or result taking

place in the things themselves, with the exception of change of place,

is not given to us by intuition. Now by means of mere relations, a

thing cannot be known in itself; and it may therefore be fairly

concluded, that, as through the external sense nothing but mere

representations of relations are given us, the said external sense in

its representation can contain only the relation of the object to the

subject, but not the essential nature of the object as a thing in

itself.

The same is the case with the internal intuition, not only because, in

the internal intuition, the representation of the external senses

constitutes the material with which the mind is occupied; but because

time, in which we place, and which itself antecedes the consciousness

of, these representations in experience, and which, as the formal

condition of the mode according to which objects are placed in the

mind, lies at the foundation of them, contains relations of the

successive, the coexistent, and of that which always must be coexistent

with succession, the permanent. Now that which, as representation, can

antecede every exercise of thought (of an object), is intuition; and

when it contains nothing but relations, it is the form of the

intuition, which, as it presents us with no representation, except in

so far as something is placed in the mind, can be nothing else than the

mode in which the mind is affected by its own activity, to wit—its

presenting to itself representations, consequently the mode in which

the mind is affected by itself; that is, it can be nothing but an

internal sense in respect to its form. Everything that is represented

through the medium of sense is so far phenomenal; consequently, we must

either refuse altogether to admit an internal sense, or the subject,

which is the object of that sense, could only be represented by it as

phenomenon, and not as it would judge of itself, if its intuition were

pure spontaneous activity, that is, were intellectual. The difficulty

here lies wholly in the question: How can the subject have an internal

intuition of itself? But this difficulty is common to every theory. The

consciousness of self (apperception) is the simple representation of

the “ego”; and if by means of that representation alone, all the

manifold representations in the subject were spontaneously given, then

our internal intuition would be intellectual. This consciousness in man

requires an internal perception of the manifold representations which

are previously given in the subject; and the manner in which these

representations are given in the mind without spontaneity, must, on

account of this difference (the want of spontaneity), be called

sensibility. If the faculty of self-consciousness is to apprehend what

lies in the mind, it must all act that and can in this way alone

produce an intuition of self. But the form of this intuition, which

lies in the original constitution of the mind, determines, in the

representation of time, the manner in which the manifold

representations are to combine themselves in the mind; since the

subject intuites itself, not as it would represent itself immediately

and spontaneously, but according to the manner in which the mind is

internally affected, consequently, as it appears, and not as it is.

III. When we say that the intuition of external objects, and also the

self-intuition of the subject, represent both, objects and subject, in

space and time, as they affect our senses, that is, as they appear—this

is by no means equivalent to asserting that these objects are mere

illusory appearances. For when we speak of things as phenomena, the

objects, nay, even the properties which we ascribe to them, are looked

upon as really given; only that, in so far as this or that property

depends upon the mode of intuition of the subject, in the relation of

the given object to the subject, the object as phenomenon is to be

distinguished from the object as a thing in itself. Thus I do not say

that bodies seem or appear to be external to me, or that my soul seems

merely to be given in my self-consciousness, although I maintain that

the properties of space and time, in conformity to which I set both, as

the condition of their existence, abide in my mode of intuition, and

not in the objects in themselves. It would be my own fault, if out of

that which I should reckon as phenomenon, I made mere illusory

appearance.[12] But this will not happen, because of our principle of

the ideality of all sensuous intuitions. On the contrary, if we ascribe

objective reality to these forms of representation, it becomes

impossible to avoid changing everything into mere appearance. For if we

regard space and time as properties, which must be found in objects as

things in themselves, as sine quibus non of the possibility of their

existence, and reflect on the absurdities in which we then find

ourselves involved, inasmuch as we are compelled to admit the existence

of two infinite things, which are nevertheless not substances, nor

anything really inhering in substances, nay, to admit that they are the

necessary conditions of the existence of all things, and moreover, that

they must continue to exist, although all existing things were

annihilated—we cannot blame the good Berkeley for degrading bodies to

mere illusory appearances. Nay, even our own existence, which would in

this case depend upon the self-existent reality of such a mere

nonentity as time, would necessarily be changed with it into mere

appearance—an absurdity which no one has as yet been guilty of.

[12] The predicates of the phenomenon can be affixed to the object

itself in relation to our sensuous faculty; for example, the red

colour or the perfume to the rose. But (illusory) appearance never can

be attributed as a predicate to an object, for this very reason, that

it attributes to this object in itself that which belongs to it only

in relation to our sensuous faculty, or to the subject in general,

e.g., the two handles which were formerly ascribed to Saturn. That

which is never to be found in the object itself, but always in the

relation of the object to the subject, and which moreover is

inseparable from our representation of the object, we denominate

phenomenon. Thus the predicates of space and time are rightly

attributed to objects of the senses as such, and in this there is no

illusion. On the contrary, if I ascribe redness of the rose as a thing

in itself, or to Saturn his handles, or extension to all external

objects, considered as things in themselves, without regarding the

determinate relation of these objects to the subject, and without

limiting my judgement to that relation—then, and then only, arises

illusion.

IV. In natural theology, where we think of an object—God—which never

can be an object of intuition to us, and even to himself can never be

an object of sensuous intuition, we carefully avoid attributing to his

intuition the conditions of space and time—and intuition all his

cognition must be, and not thought, which always includes limitation.

But with what right can we do this if we make them forms of objects as

things in themselves, and such, moreover, as would continue to exist as

à priori conditions of the existence of things, even though the things

themselves were annihilated? For as conditions of all existence in

general, space and time must be conditions of the existence of the

Supreme Being also. But if we do not thus make them objective forms of

all things, there is no other way left than to make them subjective

forms of our mode of intuition—external and internal; which is called

sensuous, because it is not primitive, that is, is not such as gives in

itself the existence of the object of the intuition (a mode of

intuition which, so far as we can judge, can belong only to the

Creator), but is dependent on the existence of the object, is possible,

therefore, only on condition that the representative faculty of the

subject is affected by the object.

It is, moreover, not necessary that we should limit the mode of

intuition in space and time to the sensuous faculty of man. It may well

be that all finite thinking beings must necessarily in this respect

agree with man (though as to this we cannot decide), but sensibility

does not on account of this universality cease to be sensibility, for

this very reason, that it is a deduced (intuitus derivativus), and not

an original (intuitus originarius), consequently not an intellectual

intuition, and this intuition, as such, for reasons above mentioned,

seems to belong solely to the Supreme Being, but never to a being

dependent, quoad its existence, as well as its intuition (which its

existence determines and limits relatively to given objects). This

latter remark, however, must be taken only as an illustration, and not

as any proof of the truth of our æsthetical theory.

§ 10. Conclusion of the Transcendental Æsthetic.

We have now completely before us one part of the solution of the grand

general problem of transcendental philosophy, namely, the question:

“How are synthetical propositions à priori possible?” That is to say,

we have shown that we are in possession of pure à priori intuitions,

namely, space and time, in which we find, when in a judgement à priori

we pass out beyond the given conception, something which is not

discoverable in that conception, but is certainly found à priori in the

intuition which corresponds to the conception, and can be united

synthetically with it. But the judgements which these pure intuitions

enable us to make, never reach farther than to objects of the senses,

and are valid only for objects of possible experience.

Second Part—TRANSCENDENTAL LOGIC

INTRODUCTION. Idea of a Transcendental Logic.

I. Of Logic in General.

Our knowledge springs from two main sources in the mind, first of which

is the faculty or power of receiving representations (receptivity for

impressions); the second is the power of cognizing by means of these

representations (spontaneity in the production of conceptions). Through

the first an object is given to us; through the second, it is, in

relation to the representation (which is a mere determination of the

mind), thought. Intuition and conceptions constitute, therefore, the

elements of all our knowledge, so that neither conceptions without an

intuition in some way corresponding to them, nor intuition without

conceptions, can afford us a cognition. Both are either pure or

empirical. They are empirical, when sensation (which presupposes the

actual presence of the object) is contained in them; and pure, when no

sensation is mixed with the representation. Sensations we may call the

matter of sensuous cognition. Pure intuition consequently contains

merely the form under which something is intuited, and pure conception

only the form of the thought of an object. Only pure intuitions and

pure conceptions are possible à priori; the empirical only à

posteriori.

We apply the term sensibility to the receptivity of the mind for

impressions, in so far as it is in some way affected; and, on the other

hand, we call the faculty of spontaneously producing representations,

or the spontaneity of cognition, understanding. Our nature is so

constituted that intuition with us never can be other than sensuous,

that is, it contains only the mode in which we are affected by objects.

On the other hand, the faculty of thinking the object of sensuous

intuition is the understanding. Neither of these faculties has a

preference over the other. Without the sensuous faculty no object would

be given to us, and without the understanding no object would be

thought. Thoughts without content are void; intuitions without

conceptions, blind. Hence it is as necessary for the mind to make its

conceptions sensuous (that is, to join to them the object in

intuition), as to make its intuitions intelligible (that is, to bring

them under conceptions). Neither of these faculties can exchange its

proper function. Understanding cannot intuite, and the sensuous faculty

cannot think. In no other way than from the united operation of both,

can knowledge arise. But no one ought, on this account, to overlook the

difference of the elements contributed by each; we have rather great

reason carefully to separate and distinguish them. We therefore

distinguish the science of the laws of sensibility, that is, æsthetic,

from the science of the laws of the understanding, that is, logic.

Now, logic in its turn may be considered as twofold—namely, as logic of

the general, or of the particular use of the understanding. The first

contains the absolutely necessary laws of thought, without which no use

whatsoever of the understanding is possible, and gives laws therefore

to the understanding, without regard to the difference of objects on

which it may be employed. The logic of the particular use of the

understanding contains the laws of correct thinking upon a particular

class of objects. The former may be called elemental logic—the latter,

the organon of this or that particular science. The latter is for the

most part employed in the schools, as a propædeutic to the sciences,

although, indeed, according to the course of human reason, it is the

last thing we arrive at, when the science has been already matured, and

needs only the finishing touches towards its correction and completion;

for our knowledge of the objects of our attempted science must be

tolerably extensive and complete before we can indicate the laws by

which a science of these objects can be established.

General logic is again either pure or applied. In the former, we

abstract all the empirical conditions under which the understanding is

exercised; for example, the influence of the senses, the play of the

fantasy or imagination, the laws of the memory, the force of habit, of

inclination, etc., consequently also, the sources of prejudice—in a

word, we abstract all causes from which particular cognitions arise,

because these causes regard the understanding under certain

circumstances of its application, and, to the knowledge of them

experience is required. Pure general logic has to do, therefore, merely

with pure à priori principles, and is a canon of understanding and

reason, but only in respect of the formal part of their use, be the

content what it may, empirical or transcendental. General logic is

called applied, when it is directed to the laws of the use of the

understanding, under the subjective empirical conditions which

psychology teaches us. It has therefore empirical principles, although,

at the same time, it is in so far general, that it applies to the

exercise of the understanding, without regard to the difference of

objects. On this account, moreover, it is neither a canon of the

understanding in general, nor an organon of a particular science, but

merely a cathartic of the human understanding.

In general logic, therefore, that part which constitutes pure logic

must be carefully distinguished from that which constitutes applied

(though still general) logic. The former alone is properly science,

although short and dry, as the methodical exposition of an elemental

doctrine of the understanding ought to be. In this, therefore,

logicians must always bear in mind two rules:

1. As general logic, it makes abstraction of all content of the

cognition of the understanding, and of the difference of objects, and

has to do with nothing but the mere form of thought.

2. As pure logic, it has no empirical principles, and consequently

draws nothing (contrary to the common persuasion) from psychology,

which therefore has no influence on the canon of the understanding. It

is a demonstrated doctrine, and everything in it must be certain

completely à priori.

What I called applied logic (contrary to the common acceptation of this

term, according to which it should contain certain exercises for the

scholar, for which pure logic gives the rules), is a representation of

the understanding, and of the rules of its necessary employment in

concreto, that is to say, under the accidental conditions of the

subject, which may either hinder or promote this employment, and which

are all given only empirically. Thus applied logic treats of attention,

its impediments and consequences, of the origin of error, of the state

of doubt, hesitation, conviction, etc., and to it is related pure

general logic in the same way that pure morality, which contains only

the necessary moral laws of a free will, is related to practical

ethics, which considers these laws under all the impediments of

feelings, inclinations, and passions to which men are more or less

subjected, and which never can furnish us with a true and demonstrated

science, because it, as well as applied logic, requires empirical and

psychological principles.

II. Of Transcendental Logic.

General logic, as we have seen, makes abstraction of all content of

cognition, that is, of all relation of cognition to its object, and

regards only the logical form in the relation of cognitions to each

other, that is, the form of thought in general. But as we have both

pure and empirical intuitions (as transcendental æsthetic proves), in

like manner a distinction might be drawn between pure and empirical

thought (of objects). In this case, there would exist a kind of logic,

in which we should not make abstraction of all content of cognition;

for or logic which should comprise merely the laws of pure thought (of

an object), would of course exclude all those cognitions which were of

empirical content. This kind of logic would also examine the origin of

our cognitions of objects, so far as that origin cannot be ascribed to

the objects themselves; while, on the contrary, general logic has

nothing to do with the origin of our cognitions, but contemplates our

representations, be they given primitively à priori in ourselves, or be

they only of empirical origin, solely according to the laws which the

understanding observes in employing them in the process of thought, in

relation to each other. Consequently, general logic treats of the form

of the understanding only, which can be applied to representations,

from whatever source they may have arisen.

And here I shall make a remark, which the reader must bear well in mind

in the course of the following considerations, to wit, that not every

cognition à priori, but only those through which we cognize that and

how certain representations (intuitions or conceptions) are applied or

are possible only à priori; that is to say, the à priori possibility of

cognition and the à priori use of it are transcendental. Therefore

neither is space, nor any à priori geometrical determination of space,

a transcendental Representation, but only the knowledge that such a

representation is not of empirical origin, and the possibility of its

relating to objects of experience, although itself à priori, can be

called transcendental. So also, the application of space to objects in

general would be transcendental; but if it be limited to objects of

sense it is empirical. Thus, the distinction of the transcendental and

empirical belongs only to the critique of cognitions, and does not

concern the relation of these to their object.

Accordingly, in the expectation that there may perhaps be conceptions

which relate à priori to objects, not as pure or sensuous intuitions,

but merely as acts of pure thought (which are therefore conceptions,

but neither of empirical nor æsthetical origin)—in this expectation, I

say, we form to ourselves, by anticipation, the idea of a science of

pure understanding and rational cognition, by means of which we may

cogitate objects entirely à priori. A science of this kind, which

should determine the origin, the extent, and the objective validity of

such cognitions, must be called transcendental logic, because it has

not, like general logic, to do with the laws of understanding and

reason in relation to empirical as well as pure rational cognitions

without distinction, but concerns itself with these only in an à priori

relation to objects.

III. Of the Division of General Logic into Analytic and Dialectic.

The old question with which people sought to push logicians into a

corner, so that they must either have recourse to pitiful sophisms or

confess their ignorance, and consequently the vanity of their whole

art, is this: “What is truth?” The definition of the word truth, to

wit, “the accordance of the cognition with its object,” is presupposed

in the question; but we desire to be told, in the answer to it, what is

the universal and secure criterion of the truth of every cognition.

To know what questions we may reasonably propose is in itself a strong

evidence of sagacity and intelligence. For if a question be in itself

absurd and unsusceptible of a rational answer, it is attended with the

danger—not to mention the shame that falls upon the person who proposes

it—of seducing the unguarded listener into making absurd answers, and

we are presented with the ridiculous spectacle of one (as the ancients

said) “milking the he-goat, and the other holding a sieve.”

If truth consists in the accordance of a cognition with its object,

this object must be, ipso facto, distinguished from all others; for a

cognition is false if it does not accord with the object to which it

relates, although it contains something which may be affirmed of other

objects. Now an universal criterion of truth would be that which is

valid for all cognitions, without distinction of their objects. But it

is evident that since, in the case of such a criterion, we make

abstraction of all the content of a cognition (that is, of all relation

to its object), and truth relates precisely to this content, it must be

utterly absurd to ask for a mark of the truth of this content of

cognition; and that, accordingly, a sufficient, and at the same time

universal, test of truth cannot possibly be found. As we have already

termed the content of a cognition its matter, we shall say: “Of the

truth of our cognitions in respect of their matter, no universal test

can be demanded, because such a demand is self-contradictory.”

On the other hand, with regard to our cognition in respect of its mere

form (excluding all content), it is equally manifest that logic, in so

far as it exhibits the universal and necessary laws of the

understanding, must in these very laws present us with criteria of

truth. Whatever contradicts these rules is false, because thereby the

understanding is made to contradict its own universal laws of thought;

that is, to contradict itself. These criteria, however, apply solely to

the form of truth, that is, of thought in general, and in so far they

are perfectly accurate, yet not sufficient. For although a cognition

may be perfectly accurate as to logical form, that is, not

self-contradictory, it is notwithstanding quite possible that it may

not stand in agreement with its object. Consequently, the merely

logical criterion of truth, namely, the accordance of a cognition with

the universal and formal laws of understanding and reason, is nothing

more than the conditio sine qua non, or negative condition of all

truth. Farther than this logic cannot go, and the error which depends

not on the form, but on the content of the cognition, it has no test to

discover.

General logic, then, resolves the whole formal business of

understanding and reason into its elements, and exhibits them as

principles of all logical judging of our cognitions. This part of logic

may, therefore, be called analytic, and is at least the negative test

of truth, because all cognitions must first of an be estimated and

tried according to these laws before we proceed to investigate them in

respect of their content, in order to discover whether they contain

positive truth in regard to their object. Because, however, the mere

form of a cognition, accurately as it may accord with logical laws, is

insufficient to supply us with material (objective) truth, no one, by

means of logic alone, can venture to predicate anything of or decide

concerning objects, unless he has obtained, independently of logic,

well-grounded information about them, in order afterwards to examine,

according to logical laws, into the use and connection, in a cohering

whole, of that information, or, what is still better, merely to test it

by them. Notwithstanding, there lies so seductive a charm in the

possession of a specious art like this—an art which gives to all our

cognitions the form of the understanding, although with respect to the

content thereof we may be sadly deficient—that general logic, which is

merely a canon of judgement, has been employed as an organon for the

actual production, or rather for the semblance of production, of

objective assertions, and has thus been grossly misapplied. Now general

logic, in its assumed character of organon, is called dialectic.

Different as are the significations in which the ancients used this

term for a science or an art, we may safely infer, from their actual

employment of it, that with them it was nothing else than a logic of

illusion—a sophistical art for giving ignorance, nay, even intentional

sophistries, the colouring of truth, in which the thoroughness of

procedure which logic requires was imitated, and their topic employed

to cloak the empty pretensions. Now it may be taken as a safe and

useful warning, that general logic, considered as an organon, must

always be a logic of illusion, that is, be dialectical, for, as it

teaches us nothing whatever respecting the content of our cognitions,

but merely the formal conditions of their accordance with the

understanding, which do not relate to and are quite indifferent in

respect of objects, any attempt to employ it as an instrument (organon)

in order to extend and enlarge the range of our knowledge must end in

mere prating; any one being able to maintain or oppose, with some

appearance of truth, any single assertion whatever.

Such instruction is quite unbecoming the dignity of philosophy. For

these reasons we have chosen to denominate this part of logic

dialectic, in the sense of a critique of dialectical illusion, and we

wish the term to be so understood in this place.

IV. Of the Division of Transcendental Logic into Transcendental

Analytic and Dialectic.

In transcendental logic we isolate the understanding (as in

transcendental æsthetic the sensibility) and select from our cognition

merely that part of thought which has its origin in the understanding

alone. The exercise of this pure cognition, however, depends upon this

as its condition, that objects to which it may be applied be given to

us in intuition, for without intuition the whole of our cognition is

without objects, and is therefore quite void. That part of

transcendental logic, then, which treats of the elements of pure

cognition of the understanding, and of the principles without which no

object at all can be thought, is transcendental analytic, and at the

same time a logic of truth. For no cognition can contradict it, without

losing at the same time all content, that is, losing all reference to

an object, and therefore all truth. But because we are very easily

seduced into employing these pure cognitions and principles of the

understanding by themselves, and that even beyond the boundaries of

experience, which yet is the only source whence we can obtain matter

(objects) on which those pure conceptions may be employed—understanding

runs the risk of making, by means of empty sophisms, a material and

objective use of the mere formal principles of the pure understanding,

and of passing judgements on objects without distinction—objects which

are not given to us, nay, perhaps cannot be given to us in any way.

Now, as it ought properly to be only a canon for judging of the

empirical use of the understanding, this kind of logic is misused when

we seek to employ it as an organon of the universal and unlimited

exercise of the understanding, and attempt with the pure understanding

alone to judge synthetically, affirm, and determine respecting objects

in general. In this case the exercise of the pure understanding becomes

dialectical. The second part of our transcendental logic must therefore

be a critique of dialectical illusion, and this critique we shall term

transcendental dialectic—not meaning it as an art of producing

dogmatically such illusion (an art which is unfortunately too current

among the practitioners of metaphysical juggling), but as a critique of

understanding and reason in regard to their hyperphysical use. This

critique will expose the groundless nature of the pretensions of these

two faculties, and invalidate their claims to the discovery and

enlargement of our cognitions merely by means of transcendental

principles, and show that the proper employment of these faculties is

to test the judgements made by the pure understanding, and to guard it

from sophistical delusion.

FIRST DIVISION. TRANSCENDENTAL LOGIC. TRANSCENDENTAL ANALYTIC. § 1

Transcendental analytic is the dissection of the whole of our à priori

knowledge into the elements of the pure cognition of the understanding.

In order to effect our purpose, it is necessary: (1) That the

conceptions be pure and not empirical; (2) That they belong not to

intuition and sensibility, but to thought and understanding; (3) That

they be elementary conceptions, and as such, quite different from

deduced or compound conceptions; (4) That our table of these elementary

conceptions be complete, and fill up the whole sphere of the pure

understanding. Now this completeness of a science cannot be accepted

with confidence on the guarantee of a mere estimate of its existence in

an aggregate formed only by means of repeated experiments and attempts.

The completeness which we require is possible only by means of an idea

of the totality of the à priori cognition of the understanding, and

through the thereby determined division of the conceptions which form

the said whole; consequently, only by means of their connection in a

system. Pure understanding distinguishes itself not merely from

everything empirical, but also completely from all sensibility. It is a

unity self-subsistent, self-sufficient, and not to be enlarged by any

additions from without. Hence the sum of its cognition constitutes a

system to be determined by and comprised under an idea; and the

completeness and articulation of this system can at the same time serve

as a test of the correctness and genuineness of all the parts of

cognition that belong to it. The whole of this part of transcendental

logic consists of two books, of which the one contains the conceptions,

and the other the principles of pure understanding.

BOOK I. Analytic of Conceptions. § 2

By the term Analytic of Conceptions, I do not understand the analysis

of these, or the usual process in philosophical investigations of

dissecting the conceptions which present themselves, according to their

content, and so making them clear; but I mean the hitherto little

attempted dissection of the faculty of understanding itself, in order

to investigate the possibility of conceptions à priori, by looking for

them in the understanding alone, as their birthplace, and analysing the

pure use of this faculty. For this is the proper duty of a

transcendental philosophy; what remains is the logical treatment of the

conceptions in philosophy in general. We shall therefore follow up the

pure conceptions even to their germs and beginnings in the human

understanding, in which they lie, until they are developed on occasions

presented by experience, and, freed by the same understanding from the

empirical conditions attaching to them, are set forth in their

unalloyed purity.

Chapter I. Of the Transcendental Clue to the Discovery of all Pure

Conceptions of the Understanding

Introductory § 3

When we call into play a faculty of cognition, different conceptions

manifest themselves according to the different circumstances, and make

known this faculty, and assemble themselves into a more or less

extensive collection, according to the time or penetration that has

been applied to the consideration of them. Where this process,

conducted as it is mechanically, so to speak, will end, cannot be

determined with certainty. Besides, the conceptions which we discover

in this haphazard manner present themselves by no means in order and

systematic unity, but are at last coupled together only according to

resemblances to each other, and arranged in series, according to the

quantity of their content, from the simpler to the more complex—series

which are anything but systematic, though not altogether without a

certain kind of method in their construction.

Transcendental philosophy has the advantage, and moreover the duty, of

searching for its conceptions according to a principle; because these

conceptions spring pure and unmixed out of the understanding as an

absolute unity, and therefore must be connected with each other

according to one conception or idea. A connection of this kind,

however, furnishes us with a ready prepared rule, by which its proper

place may be assigned to every pure conception of the understanding,

and the completeness of the system of all be determined à priori—both

which would otherwise have been dependent on mere choice or chance.

Section I. Of the Logical Use of the Understanding in General § 4

The understanding was defined above only negatively, as a non-sensuous

faculty of cognition. Now, independently of sensibility, we cannot

possibly have any intuition; consequently, the understanding is no

faculty of intuition. But besides intuition there is no other mode of

cognition, except through conceptions; consequently, the cognition of

every, at least of every human, understanding is a cognition through

conceptions—not intuitive, but discursive. All intuitions, as sensuous,

depend on affections; conceptions, therefore, upon functions. By the

word function I understand the unity of the act of arranging diverse

representations under one common representation. Conceptions, then, are

based on the spontaneity of thought, as sensuous intuitions are on the

receptivity of impressions. Now, the understanding cannot make any

other use of these conceptions than to judge by means of them. As no

representation, except an intuition, relates immediately to its object,

a conception never relates immediately to an object, but only to some

other representation thereof, be that an intuition or itself a

conception. A judgement, therefore, is the mediate cognition of an

object, consequently the representation of a representation of it. In

every judgement there is a conception which applies to, and is valid

for many other conceptions, and which among these comprehends also a

given representation, this last being immediately connected with an

object. For example, in the judgement—“All bodies are divisible,” our

conception of divisible applies to various other conceptions; among

these, however, it is here particularly applied to the conception of

body, and this conception of body relates to certain phenomena which

occur to us. These objects, therefore, are mediately represented by the

conception of divisibility. All judgements, accordingly, are functions

of unity in our representations, inasmuch as, instead of an immediate,

a higher representation, which comprises this and various others, is

used for our cognition of the object, and thereby many possible

cognitions are collected into one. But we can reduce all acts of the

understanding to judgements, so that understanding may be represented

as the faculty of judging. For it is, according to what has been said

above, a faculty of thought. Now thought is cognition by means of

conceptions. But conceptions, as predicates of possible judgements,

relate to some representation of a yet undetermined object. Thus the

conception of body indicates something—for example, metal—which can be

cognized by means of that conception. It is therefore a conception, for

the reason alone that other representations are contained under it, by

means of which it can relate to objects. It is therefore the predicate

to a possible judgement; for example: “Every metal is a body.” All the

functions of the understanding therefore can be discovered, when we can

completely exhibit the functions of unity in judgements. And that this

may be effected very easily, the following section will show.

Section II. Of the Logical Function of the Understanding in Judgements

§ 5

If we abstract all the content of a judgement, and consider only the

intellectual form thereof, we find that the function of thought in a

judgement can be brought under four heads, of which each contains three

momenta. These may be conveniently represented in the following table:

1

_Quantity of judgements_

Universal

Particular

Singular

2 3

_Quality Relation_

Affirmative Categorical

Negative Hypothetical

Infinite Disjunctive

4

_Modality_

Problematical

Assertorical

Apodeictical

As this division appears to differ in some, though not essential

points, from the usual technique of logicians, the following

observations, for the prevention of otherwise possible

misunderstanding, will not be without their use.

1. Logicians say, with justice, that in the use of judgements in

syllogisms, singular judgements may be treated like universal ones.

For, precisely because a singular judgement has no extent at all, its

predicate cannot refer to a part of that which is contained in the

conception of the subject and be excluded from the rest. The predicate

is valid for the whole conception just as if it were a general

conception, and had extent, to the whole of which the predicate

applied. On the other hand, let us compare a singular with a general

judgement, merely as a cognition, in regard to quantity. The singular

judgement relates to the general one, as unity to infinity, and is

therefore in itself essentially different. Thus, if we estimate a

singular judgement (_judicium singulare_) not merely according to its

intrinsic validity as a judgement, but also as a cognition generally,

according to its quantity in comparison with that of other cognitions,

it is then entirely different from a general judgement (_judicium

commune_), and in a complete table of the momenta of thought deserves a

separate place—though, indeed, this would not be necessary in a logic

limited merely to the consideration of the use of judgements in

reference to each other.

2. In like manner, in transcendental logic, infinite must be

distinguished from affirmative judgements, although in general logic

they are rightly enough classed under affirmative. General logic

abstracts all content of the predicate (though it be negative), and

only considers whether the said predicate be affirmed or denied of the

subject. But transcendental logic considers also the worth or content

of this logical affirmation—an affirmation by means of a merely

negative predicate, and inquires how much the sum total of our

cognition gains by this affirmation. For example, if I say of the soul,

“It is not mortal”—by this negative judgement I should at least ward

off error. Now, by the proposition, “The soul is not mortal,” I have,

in respect of the logical form, really affirmed, inasmuch as I thereby

place the soul in the unlimited sphere of immortal beings. Now, because

of the whole sphere of possible existences, the mortal occupies one

part, and the immortal the other, neither more nor less is affirmed by

the proposition than that the soul is one among the infinite multitude

of things which remain over, when I take away the whole mortal part.

But by this proceeding we accomplish only this much, that the infinite

sphere of all possible existences is in so far limited that the mortal

is excluded from it, and the soul is placed in the remaining part of

the extent of this sphere. But this part remains, notwithstanding this

exception, infinite, and more and more parts may be taken away from the

whole sphere, without in the slightest degree thereby augmenting or

affirmatively determining our conception of the soul. These judgements,

therefore, infinite in respect of their logical extent, are, in respect

of the content of their cognition, merely limitative; and are

consequently entitled to a place in our transcendental table of all the

momenta of thought in judgements, because the function of the

understanding exercised by them may perhaps be of importance in the

field of its pure à priori cognition.

3. All relations of thought in judgements are those (a) of the

predicate to the subject; (b) of the principle to its consequence; (c)

of the divided cognition and all the members of the division to each

other. In the first of these three classes, we consider only two

conceptions; in the second, two judgements; in the third, several

judgements in relation to each other. The hypothetical proposition, “If

perfect justice exists, the obstinately wicked are punished,” contains

properly the relation to each other of two propositions, namely,

“Perfect justice exists,” and “The obstinately wicked are punished.”

Whether these propositions are in themselves true is a question not

here decided. Nothing is cogitated by means of this judgement except a

certain consequence. Finally, the disjunctive judgement contains a

relation of two or more propositions to each other—a relation not of

consequence, but of logical opposition, in so far as the sphere of the

one proposition excludes that of the other. But it contains at the same

time a relation of community, in so far as all the propositions taken

together fill up the sphere of the cognition. The disjunctive judgement

contains, therefore, the relation of the parts of the whole sphere of a

cognition, since the sphere of each part is a complemental part of the

sphere of the other, each contributing to form the sum total of the

divided cognition. Take, for example, the proposition, “The world

exists either through blind chance, or through internal necessity, or

through an external cause.” Each of these propositions embraces a part

of the sphere of our possible cognition as to the existence of a world;

all of them taken together, the whole sphere. To take the cognition out

of one of these spheres, is equivalent to placing it in one of the

others; and, on the other hand, to place it in one sphere is equivalent

to taking it out of the rest. There is, therefore, in a disjunctive

judgement a certain community of cognitions, which consists in this,

that they mutually exclude each other, yet thereby determine, as a

whole, the true cognition, inasmuch as, taken together, they make up

the complete content of a particular given cognition. And this is all

that I find necessary, for the sake of what follows, to remark in this

place.

4. The modality of judgements is a quite peculiar function, with this

distinguishing characteristic, that it contributes nothing to the

content of a judgement (for besides quantity, quality, and relation,

there is nothing more that constitutes the content of a judgement), but

concerns itself only with the value of the copula in relation to

thought in general. Problematical judgements are those in which the

affirmation or negation is accepted as merely possible (ad libitum). In

the assertorical, we regard the proposition as real (true); in the

apodeictical, we look on it as necessary.[13] Thus the two judgements

(antecedens et consequens), the relation of which constitutes a

hypothetical judgement, likewise those (the members of the division) in

whose reciprocity the disjunctive consists, are only problematical. In

the example above given the proposition, “There exists perfect

justice,” is not stated assertorically, but as an ad libitum judgement,

which someone may choose to adopt, and the consequence alone is

assertorical. Hence such judgements may be obviously false, and yet,

taken problematically, be conditions of our cognition of the truth.

Thus the proposition, “The world exists only by blind chance,” is in

the disjunctive judgement of problematical import only: that is to say,

one may accept it for the moment, and it helps us (like the indication

of the wrong road among all the roads that one can take) to find out

the true proposition. The problematical proposition is, therefore, that

which expresses only logical possibility (which is not objective); that

is, it expresses a free choice to admit the validity of such a

proposition—a merely arbitrary reception of it into the understanding.

The assertorical speaks of logical reality or truth; as, for example,

in a hypothetical syllogism, the antecedens presents itself in a

problematical form in the major, in an assertorical form in the minor,

and it shows that the proposition is in harmony with the laws of the

understanding. The apodeictical proposition cogitates the assertorical

as determined by these very laws of the understanding, consequently as

affirming à priori, and in this manner it expresses logical necessity.

Now because all is here gradually incorporated with the

understanding—inasmuch as in the first place we judge problematically;

then accept assertorically our judgement as true; lastly, affirm it as

inseparably united with the understanding, that is, as necessary and

apodeictical—we may safely reckon these three functions of modality as

so many momenta of thought.

[13] Just as if thought were in the first instance a function of the

understanding; in the second, of judgement; in the third, of reason. A

remark which will be explained in the sequel.

Section III. Of the Pure Conceptions of the Understanding, or

Categories § 6

General logic, as has been repeatedly said, makes abstraction of all

content of cognition, and expects to receive representations from some

other quarter, in order, by means of analysis, to convert them into

conceptions. On the contrary, transcendental logic has lying before it

the manifold content of à priori sensibility, which transcendental

æsthetic presents to it in order to give matter to the pure conceptions

of the understanding, without which transcendental logic would have no

content, and be therefore utterly void. Now space and time contain an

infinite diversity of determinations of pure à priori intuition, but

are nevertheless the condition of the mind’s receptivity, under which

alone it can obtain representations of objects, and which,

consequently, must always affect the conception of these objects. But

the spontaneity of thought requires that this diversity be examined

after a certain manner, received into the mind, and connected, in order

afterwards to form a cognition out of it. This Process I call

synthesis.

By the word synthesis, in its most general signification, I understand

the process of joining different representations to each other and of

comprehending their diversity in one cognition. This synthesis is pure

when the diversity is not given empirically but à priori (as that in

space and time). Our representations must be given previously to any

analysis of them; and no conceptions can arise, quoad their content,

analytically. But the synthesis of a diversity (be it given à priori or

empirically) is the first requisite for the production of a cognition,

which in its beginning, indeed, may be crude and confused, and

therefore in need of analysis—still, synthesis is that by which alone

the elements of our cognitions are collected and united into a certain

content, consequently it is the first thing on which we must fix our

attention, if we wish to investigate the origin of our knowledge.

Synthesis, generally speaking, is, as we shall afterwards see, the mere

operation of the imagination—a blind but indispensable function of the

soul, without which we should have no cognition whatever, but of the

working of which we are seldom even conscious. But to reduce this

synthesis to conceptions is a function of the understanding, by means

of which we attain to cognition, in the proper meaning of the term.

Pure synthesis, represented generally, gives us the pure conception of

the understanding. But by this pure synthesis, I mean that which rests

upon a basis of à priori synthetical unity. Thus, our numeration (and

this is more observable in large numbers) is a synthesis according to

conceptions, because it takes place according to a common basis of

unity (for example, the decade). By means of this conception,

therefore, the unity in the synthesis of the manifold becomes

necessary.

By means of analysis different representations are brought under one

conception—an operation of which general logic treats. On the other

hand, the duty of transcendental logic is to reduce to conceptions, not

representations, but the pure synthesis of representations. The first

thing which must be given to us for the sake of the à priori cognition

of all objects, is the diversity of the pure intuition; the synthesis

of this diversity by means of the imagination is the second; but this

gives, as yet, no cognition. The conceptions which give unity to this

pure synthesis, and which consist solely in the representation of this

necessary synthetical unity, furnish the third requisite for the

cognition of an object, and these conceptions are given by the

understanding.

The same function which gives unity to the different representation in

a judgement, gives also unity to the mere synthesis of different

representations in an intuition; and this unity we call the pure

conception of the understanding. Thus, the same understanding, and by

the same operations, whereby in conceptions, by means of analytical

unity, it produced the logical form of a judgement, introduces, by

means of the synthetical unity of the manifold in intuition, a

transcendental content into its representations, on which account they

are called pure conceptions of the understanding, and they apply à

priori to objects, a result not within the power of general logic.

In this manner, there arise exactly so many pure conceptions of the

understanding, applying à priori to objects of intuition in general, as

there are logical functions in all possible judgements. For there is no

other function or faculty existing in the understanding besides those

enumerated in that table. These conceptions we shall, with Aristotle,

call categories, our purpose being originally identical with his,

notwithstanding the great difference in the execution.

TABLE OF THE CATEGORIES

1 2

_Of Quantity Of Quality_

Unity Reality

Plurality Negation

Totality Limitation

3

_Of Relation_

Of Inherence and Subsistence (substantia et accidens)

Of Causality and Dependence (cause and effect)

Of Community (reciprocity between the agent and patient)

4

_Of Modality_

Possibility—Impossibility

Existence—Non-existence

Necessity—Contingence

This, then, is a catalogue of all the originally pure conceptions of

the synthesis which the understanding contains à priori, and these

conceptions alone entitle it to be called a pure understanding;

inasmuch as only by them it can render the manifold of intuition

conceivable, in other words, think an object of intuition. This

division is made systematically from a common principle, namely the

faculty of judgement (which is just the same as the power of thought),

and has not arisen rhapsodically from a search at haphazard after pure

conceptions, respecting the full number of which we never could be

certain, inasmuch as we employ induction alone in our search, without

considering that in this way we can never understand wherefore

precisely these conceptions, and none others, abide in the pure

understanding. It was a design worthy of an acute thinker like

Aristotle, to search for these fundamental conceptions. Destitute,

however, of any guiding principle, he picked them up just as they

occurred to him, and at first hunted out ten, which he called

categories (predicaments). Afterwards be believed that he had

discovered five others, which were added under the name of post

predicaments. But his catalogue still remained defective. Besides,

there are to be found among them some of the modes of pure sensibility

(quando, ubi, situs, also prius, simul), and likewise an empirical

conception (motus)—which can by no means belong to this genealogical

register of the pure understanding. Moreover, there are deduced

conceptions (actio, passio) enumerated among the original conceptions,

and, of the latter, some are entirely wanting.

With regard to these, it is to be remarked, that the categories, as the

true primitive conceptions of the pure understanding, have also their

pure deduced conceptions, which, in a complete system of transcendental

philosophy, must by no means be passed over; though in a merely

critical essay we must be contented with the simple mention of the

fact.

Let it be allowed me to call these pure, but deduced conceptions of the

understanding, the predicables of the pure understanding, in

contradistinction to predicaments. If we are in possession of the

original and primitive, the deduced and subsidiary conceptions can

easily be added, and the genealogical tree of the understanding

completely delineated. As my present aim is not to set forth a complete

system, but merely the principles of one, I reserve this task for

another time. It may be easily executed by any one who will refer to

the ontological manuals, and subordinate to the category of causality,

for example, the predicables of force, action, passion; to that of

community, those of presence and resistance; to the categories of

modality, those of origination, extinction, change; and so with the

rest. The categories combined with the modes of pure sensibility, or

with one another, afford a great number of deduced à priori

conceptions; a complete enumeration of which would be a useful and not

unpleasant, but in this place a perfectly dispensable, occupation.

I purposely omit the definitions of the categories in this treatise. I

shall analyse these conceptions only so far as is necessary for the

doctrine of method, which is to form a part of this critique. In a

system of pure reason, definitions of them would be with justice

demanded of me, but to give them here would only bide from our view the

main aim of our investigation, at the same time raising doubts and

objections, the consideration of which, without injustice to our main

purpose, may be very well postponed till another opportunity.

Meanwhile, it ought to be sufficiently clear, from the little we have

already said on this subject, that the formation of a complete

vocabulary of pure conceptions, accompanied by all the requisite

explanations, is not only a possible, but an easy undertaking. The

compartments already exist; it is only necessary to fill them up; and a

systematic topic like the present, indicates with perfect precision the

proper place to which each conception belongs, while it readily points

out any that have not yet been filled up.

§ 7

Our table of the categories suggests considerations of some importance,

which may perhaps have significant results in regard to the scientific

form of all rational cognitions. For, that this table is useful in the

theoretical part of philosophy, nay, indispensable for the sketching of

the complete plan of a science, so far as that science rests upon

conceptions à priori, and for dividing it mathematically, according to

fixed principles, is most manifest from the fact that it contains all

the elementary conceptions of the understanding, nay, even the form of

a system of these in the understanding itself, and consequently

indicates all the momenta, and also the internal arrangement of a

projected speculative science, as I have elsewhere shown.[14] Here

follow some of these observations.

[14] In the “Metaphysical Principles of Natural Science.”

I. This table, which contains four classes of conceptions of the

understanding, may, in the first instance, be divided into two classes,

the first of which relates to objects of intuition—pure as well as

empirical; the second, to the existence of these objects, either in

relation to one another, or to the understanding.

The former of these classes of categories I would entitle the

mathematical, and the latter the dynamical categories. The former, as

we see, has no correlates; these are only to be found in the second

class. This difference must have a ground in the nature of the human

understanding.

II. The number of the categories in each class is always the same,

namely, three—a fact which also demands some consideration, because in

all other cases division à priori through conceptions is necessarily

dichotomy. It is to be added, that the third category in each triad

always arises from the combination of the second with the first.

Thus totality is nothing else but plurality contemplated as unity;

limitation is merely reality conjoined with negation; community is the

causality of a substance, reciprocally determining, and determined by

other substances; and finally, necessity is nothing but existence,

which is given through the possibility itself. Let it not be supposed,

however, that the third category is merely a deduced, and not a

primitive conception of the pure understanding. For the conjunction of

the first and second, in order to produce the third conception,

requires a particular function of the understanding, which is by no

means identical with those which are exercised in the first and second.

Thus, the conception of a number (which belongs to the category of

totality) is not always possible, where the conceptions of multitude

and unity exist (for example, in the representation of the infinite).

Or, if I conjoin the conception of a cause with that of a substance, it

does not follow that the conception of influence, that is, how one

substance can be the cause of something in another substance, will be

understood from that. Thus it is evident that a particular act of the

understanding is here necessary; and so in the other instances.

III. With respect to one category, namely, that of community, which is

found in the third class, it is not so easy as with the others to

detect its accordance with the form of the disjunctive judgement which

corresponds to it in the table of the logical functions.

In order to assure ourselves of this accordance, we must observe that

in every disjunctive judgement, the sphere of the judgement (that is,

the complex of all that is contained in it) is represented as a whole

divided into parts; and, since one part cannot be contained in the

other, they are cogitated as co-ordinated with, not subordinated to

each other, so that they do not determine each other unilaterally, as

in a linear series, but reciprocally, as in an aggregate—(if one member

of the division is posited, all the rest are excluded; and conversely).

Now a like connection is cogitated in a whole of things; for one thing

is not subordinated, as effect, to another as cause of its existence,

but, on the contrary, is co-ordinated contemporaneously and

reciprocally, as a cause in relation to the determination of the others

(for example, in a body—the parts of which mutually attract and repel

each other). And this is an entirely different kind of connection from

that which we find in the mere relation of the cause to the effect (the

principle to the consequence), for in such a connection the consequence

does not in its turn determine the principle, and therefore does not

constitute, with the latter, a whole—just as the Creator does not with

the world make up a whole. The process of understanding by which it

represents to itself the sphere of a divided conception, is employed

also when we think of a thing as divisible; and in the same manner as

the members of the division in the former exclude one another, and yet

are connected in one sphere, so the understanding represents to itself

the parts of the latter, as having—each of them—an existence (as

substances), independently of the others, and yet as united in one

whole.

§ 8

In the transcendental philosophy of the ancients there exists one more

leading division, which contains pure conceptions of the understanding,

and which, although not numbered among the categories, ought, according

to them, as conceptions à priori, to be valid of objects. But in this

case they would augment the number of the categories; which cannot be.

These are set forth in the proposition, so renowned among the

schoolmen—‘_Quodlibet ens est UNUM, VERUM, BONUM_.’ Now, though the

inferences from this principle were mere tautological propositions, and

though it is allowed only by courtesy to retain a place in modern

metaphysics, yet a thought which maintained itself for such a length of

time, however empty it seems to be, deserves an investigation of its

origin, and justifies the conjecture that it must be grounded in some

law of the understanding, which, as is often the case, has only been

erroneously interpreted. These pretended transcendental predicates are,

in fact, nothing but logical requisites and criteria of all cognition

of objects, and they employ, as the basis for this cognition, the

categories of quantity, namely, unity, plurality, and totality. But

these, which must be taken as material conditions, that is, as

belonging to the possibility of things themselves, they employed merely

in a formal signification, as belonging to the logical requisites of

all cognition, and yet most unguardedly changed these criteria of

thought into properties of objects, as things in themselves. Now, in

every cognition of an object, there is unity of conception, which may

be called qualitative unity, so far as by this term we understand only

the unity in our connection of the manifold; for example, unity of the

theme in a play, an oration, or a story. Secondly, there is truth in

respect of the deductions from it. The more true deductions we have

from a given conception, the more criteria of its objective reality.

This we might call the qualitative plurality of characteristic marks,

which belong to a conception as to a common foundation, but are not

cogitated as a quantity in it. Thirdly, there is perfection—which

consists in this, that the plurality falls back upon the unity of the

conception, and accords completely with that conception and with no

other. This we may denominate qualitative completeness. Hence it is

evident that these logical criteria of the possibility of cognition are

merely the three categories of quantity modified and transformed to

suit an unauthorized manner of applying them. That is to say, the three

categories, in which the unity in the production of the quantum must be

homogeneous throughout, are transformed solely with a view to the

connection of heterogeneous parts of cognition in one act of

consciousness, by means of the quality of the cognition, which is the

principle of that connection. Thus the criterion of the possibility of

a conception (not of its object) is the definition of it, in which the

unity of the conception, the truth of all that may be immediately

deduced from it, and finally, the completeness of what has been thus

deduced, constitute the requisites for the reproduction of the whole

conception. Thus also, the criterion or test of an hypothesis is the

intelligibility of the received principle of explanation, or its unity

(without help from any subsidiary hypothesis)—the truth of our

deductions from it (consistency with each other and with

experience)—and lastly, the completeness of the principle of the

explanation of these deductions, which refer to neither more nor less

than what was admitted in the hypothesis, restoring analytically and à

posteriori, what was cogitated synthetically and à priori. By the

conceptions, therefore, of unity, truth, and perfection, we have made

no addition to the transcendental table of the categories, which is

complete without them. We have, on the contrary, merely employed the

three categories of quantity, setting aside their application to

objects of experience, as general logical laws of the consistency of

cognition with itself.

Chapter II. Of the Deduction of the Pure Conceptions of the

Understanding

Section I. Of the Principles of a Transcendental Deduction in general §

9

Teachers of jurisprudence, when speaking of rights and claims,

distinguish in a cause the question of right (quid juris) from the

question of fact (quid facti), and while they demand proof of both,

they give to the proof of the former, which goes to establish right or

claim in law, the name of deduction. Now we make use of a great number

of empirical conceptions, without opposition from any one; and consider

ourselves, even without any attempt at deduction, justified in

attaching to them a sense, and a supposititious signification, because

we have always experience at hand to demonstrate their objective

reality. There exist also, however, usurped conceptions, such as

fortune, fate, which circulate with almost universal indulgence, and

yet are occasionally challenged by the question, “quid juris?” In such

cases, we have great difficulty in discovering any deduction for these

terms, inasmuch as we cannot produce any manifest ground of right,

either from experience or from reason, on which the claim to employ

them can be founded.

Among the many conceptions, which make up the very variegated web of

human cognition, some are destined for pure use à priori, independent

of all experience; and their title to be so employed always requires a

deduction, inasmuch as, to justify such use of them, proofs from

experience are not sufficient; but it is necessary to know how these

conceptions can apply to objects without being derived from experience.

I term, therefore, an examination of the manner in which conceptions

can apply à priori to objects, the transcendental deduction of

conceptions, and I distinguish it from the empirical deduction, which

indicates the mode in which conception is obtained through experience

and reflection thereon; consequently, does not concern itself with the

right, but only with the fact of our obtaining conceptions in such and

such a manner. We have already seen that we are in possession of two

perfectly different kinds of conceptions, which nevertheless agree with

each other in this, that they both apply to objects completely à

priori. These are the conceptions of space and time as forms of

sensibility, and the categories as pure conceptions of the

understanding. To attempt an empirical deduction of either of these

classes would be labour in vain, because the distinguishing

characteristic of their nature consists in this, that they apply to

their objects, without having borrowed anything from experience towards

the representation of them. Consequently, if a deduction of these

conceptions is necessary, it must always be transcendental.

Meanwhile, with respect to these conceptions, as with respect to all

our cognition, we certainly may discover in experience, if not the

principle of their possibility, yet the occasioning causes of their

production. It will be found that the impressions of sense give the

first occasion for bringing into action the whole faculty of cognition,

and for the production of experience, which contains two very

dissimilar elements, namely, a matter for cognition, given by the

senses, and a certain form for the arrangement of this matter, arising

out of the inner fountain of pure intuition and thought; and these, on

occasion given by sensuous impressions, are called into exercise and

produce conceptions. Such an investigation into the first efforts of

our faculty of cognition to mount from particular perceptions to

general conceptions is undoubtedly of great utility; and we have to

thank the celebrated Locke for having first opened the way for this

inquiry. But a deduction of the pure à priori conceptions of course

never can be made in this way, seeing that, in regard to their future

employment, which must be entirely independent of experience, they must

have a far different certificate of birth to show from that of a

descent from experience. This attempted physiological derivation, which

cannot properly be called deduction, because it relates merely to a

quaestio facti, I shall entitle an explanation of the possession of a

pure cognition. It is therefore manifest that there can only be a

transcendental deduction of these conceptions and by no means an

empirical one; also, that all attempts at an empirical deduction, in

regard to pure à priori conceptions, are vain, and can only be made by

one who does not understand the altogether peculiar nature of these

cognitions.

But although it is admitted that the only possible deduction of pure à

priori cognition is a transcendental deduction, it is not, for that

reason, perfectly manifest that such a deduction is absolutely

necessary. We have already traced to their sources the conceptions of

space and time, by means of a transcendental deduction, and we have

explained and determined their objective validity à priori. Geometry,

nevertheless, advances steadily and securely in the province of pure à

priori cognitions, without needing to ask from philosophy any

certificate as to the pure and legitimate origin of its fundamental

conception of space. But the use of the conception in this science

extends only to the external world of sense, the pure form of the

intuition of which is space; and in this world, therefore, all

geometrical cognition, because it is founded upon à priori intuition,

possesses immediate evidence, and the objects of this cognition are

given à priori (as regards their form) in intuition by and through the

cognition itself. With the pure conceptions of understanding, on the

contrary, commences the absolute necessity of seeking a transcendental

deduction, not only of these conceptions themselves, but likewise of

space, because, inasmuch as they make affirmations concerning objects

not by means of the predicates of intuition and sensibility, but of

pure thought à priori, they apply to objects without any of the

conditions of sensibility. Besides, not being founded on experience,

they are not presented with any object in à priori intuition upon

which, antecedently to experience, they might base their synthesis.

Hence results, not only doubt as to the objective validity and proper

limits of their use, but that even our conception of space is rendered

equivocal; inasmuch as we are very ready with the aid of the

categories, to carry the use of this conception beyond the conditions

of sensuous intuition—and, for this reason, we have already found a

transcendental deduction of it needful. The reader, then, must be quite

convinced of the absolute necessity of a transcendental deduction,

before taking a single step in the field of pure reason; because

otherwise he goes to work blindly, and after he has wondered about in

all directions, returns to the state of utter ignorance from which he

started. He ought, moreover, clearly to recognize beforehand the

unavoidable difficulties in his undertaking, so that he may not

afterwards complain of the obscurity in which the subject itself is

deeply involved, or become too soon impatient of the obstacles in his

path; because we have a choice of only two things—either at once to

give up all pretensions to knowledge beyond the limits of possible

experience, or to bring this critical investigation to completion.

We have been able, with very little trouble, to make it comprehensible

how the conceptions of space and time, although à priori cognitions,

must necessarily apply to external objects, and render a synthetical

cognition of these possible, independently of all experience. For

inasmuch as only by means of such pure form of sensibility an object

can appear to us, that is, be an object of empirical intuition, space

and time are pure intuitions, which contain à priori the condition of

the possibility of objects as phenomena, and an à priori synthesis in

these intuitions possesses objective validity.

On the other hand, the categories of the understanding do not represent

the conditions under which objects are given to us in intuition;

objects can consequently appear to us without necessarily connecting

themselves with these, and consequently without any necessity binding

on the understanding to contain à priori the conditions of these

objects. Thus we find ourselves involved in a difficulty which did not

present itself in the sphere of sensibility, that is to say, we cannot

discover how the subjective conditions of thought can have objective

validity, in other words, can become conditions of the possibility of

all cognition of objects; for phenomena may certainly be given to us in

intuition without any help from the functions of the understanding. Let

us take, for example, the conception of cause, which indicates a

peculiar kind of synthesis, namely, that with something, A, something

entirely different, B, is connected according to a law. It is not à

priori manifest why phenomena should contain anything of this kind (we

are of course debarred from appealing for proof to experience, for the

objective validity of this conception must be demonstrated à priori),

and it hence remains doubtful à priori, whether such a conception be

not quite void and without any corresponding object among phenomena.

For that objects of sensuous intuition must correspond to the formal

conditions of sensibility existing à priori in the mind is quite

evident, from the fact that without these they could not be objects for

us; but that they must also correspond to the conditions which

understanding requires for the synthetical unity of thought is an

assertion, the grounds for which are not so easily to be discovered.

For phenomena might be so constituted as not to correspond to the

conditions of the unity of thought; and all things might lie in such

confusion that, for example, nothing could be met with in the sphere of

phenomena to suggest a law of synthesis, and so correspond to the

conception of cause and effect; so that this conception would be quite

void, null, and without significance. Phenomena would nevertheless

continue to present objects to our intuition; for mere intuition does

not in any respect stand in need of the functions of thought.

If we thought to free ourselves from the labour of these investigations

by saying: “Experience is constantly offering us examples of the

relation of cause and effect in phenomena, and presents us with

abundant opportunity of abstracting the conception of cause, and so at

the same time of corroborating the objective validity of this

conception”; we should in this case be overlooking the fact, that the

conception of cause cannot arise in this way at all; that, on the

contrary, it must either have an à priori basis in the understanding,

or be rejected as a mere chimera. For this conception demands that

something, A, should be of such a nature that something else, B, should

follow from it necessarily, and according to an absolutely universal

law. We may certainly collect from phenomena a law, according to which

this or that usually happens, but the element of necessity is not to be

found in it. Hence it is evident that to the synthesis of cause and

effect belongs a dignity, which is utterly wanting in any empirical

synthesis; for it is no mere mechanical synthesis, by means of

addition, but a dynamical one; that is to say, the effect is not to be

cogitated as merely annexed to the cause, but as posited by and through

the cause, and resulting from it. The strict universality of this law

never can be a characteristic of empirical laws, which obtain through

induction only a comparative universality, that is, an extended range

of practical application. But the pure conceptions of the understanding

would entirely lose all their peculiar character, if we treated them

merely as the productions of experience.

Transition to the Transcendental Deduction of the Categories § 10

There are only two possible ways in which synthetical representation

and its objects can coincide with and relate necessarily to each other,

and, as it were, meet together. Either the object alone makes the

representation possible, or the representation alone makes the object

possible. In the former case, the relation between them is only

empirical, and an à priori representation is impossible. And this is

the case with phenomena, as regards that in them which is referable to

mere sensation. In the latter case—although representation alone (for

of its causality, by means of the will, we do not here speak) does not

produce the object as to its existence, it must nevertheless be à

priori determinative in regard to the object, if it is only by means of

the representation that we can cognize anything as an object. Now there

are only two conditions of the possibility of a cognition of objects;

firstly, intuition, by means of which the object, though only as

phenomenon, is given; secondly, conception, by means of which the

object which corresponds to this intuition is thought. But it is

evident from what has been said on æsthetic that the first condition,

under which alone objects can be intuited, must in fact exist, as a

formal basis for them, à priori in the mind. With this formal condition

of sensibility, therefore, all phenomena necessarily correspond,

because it is only through it that they can be phenomena at all; that

is, can be empirically intuited and given. Now the question is whether

there do not exist, à priori in the mind, conceptions of understanding

also, as conditions under which alone something, if not intuited, is

yet thought as object. If this question be answered in the affirmative,

it follows that all empirical cognition of objects is necessarily

conformable to such conceptions, since, if they are not presupposed, it

is impossible that anything can be an object of experience. Now all

experience contains, besides the intuition of the senses through which

an object is given, a conception also of an object that is given in

intuition. Accordingly, conceptions of objects in general must lie as à

priori conditions at the foundation of all empirical cognition; and

consequently, the objective validity of the categories, as à priori

conceptions, will rest upon this, that experience (as far as regards

the form of thought) is possible only by their means. For in that case

they apply necessarily and à priori to objects of experience, because

only through them can an object of experience be thought.

The whole aim of the transcendental deduction of all à priori

conceptions is to show that these conceptions are à priori conditions

of the possibility of all experience. Conceptions which afford us the

objective foundation of the possibility of experience are for that very

reason necessary. But the analysis of the experiences in which they are

met with is not deduction, but only an illustration of them, because

from experience they could never derive the attribute of necessity.

Without their original applicability and relation to all possible

experience, in which all objects of cognition present themselves, the

relation of the categories to objects, of whatever nature, would be

quite incomprehensible.

The celebrated Locke, for want of due reflection on these points, and

because he met with pure conceptions of the understanding in

experience, sought also to deduce them from experience, and yet

proceeded so inconsequently as to attempt, with their aid, to arrive it

cognitions which lie far beyond the limits of all experience. David

Hume perceived that, to render this possible, it was necessary that the

conceptions should have an à priori origin. But as he could not explain

how it was possible that conceptions which are not connected with each

other in the understanding must nevertheless be thought as necessarily

connected in the object—and it never occurred to him that the

understanding itself might, perhaps, by means of these conceptions, be

the author of the experience in which its objects were presented to

it—he was forced to drive these conceptions from experience, that is,

from a subjective necessity arising from repeated association of

experiences erroneously considered to be objective—in one word, from

habit. But he proceeded with perfect consequence and declared it to be

impossible, with such conceptions and the principles arising from them,

to overstep the limits of experience. The empirical derivation,

however, which both of these philosophers attributed to these

conceptions, cannot possibly be reconciled with the fact that we do

possess scientific à priori cognitions, namely, those of pure

mathematics and general physics.

The former of these two celebrated men opened a wide door to

extravagance—(for if reason has once undoubted right on its side, it

will not allow itself to be confined to set limits, by vague

recommendations of moderation); the latter gave himself up entirely to

scepticism—a natural consequence, after having discovered, as he

thought, that the faculty of cognition was not trustworthy. We now

intend to make a trial whether it be not possible safely to conduct

reason between these two rocks, to assign her determinate limits, and

yet leave open for her the entire sphere of her legitimate activity.

I shall merely premise an explanation of what the categories are. They

are conceptions of an object in general, by means of which its

intuition is contemplated as determined in relation to one of the

logical functions of judgement. The following will make this plain. The

function of the categorical judgement is that of the relation of

subject to predicate; for example, in the proposition: “All bodies are

divisible.” But in regard to the merely logical use of the

understanding, it still remains undetermined to which Of these two

conceptions belongs the function Of subject and to which that of

predicate. For we could also say: “Some divisible is a body.” But the

category of substance, when the conception of a body is brought under

it, determines that; and its empirical intuition in experience must be

contemplated always as subject and never as mere predicate. And so with

all the other categories.

Section II Transcendental Deduction of the pure Conceptions of the

Understanding

Of the Possibility of a Conjunction of the manifold representations

given by Sense § 11.

The manifold content in our representations can be given in an

intuition which is merely sensuous—in other words, is nothing but

susceptibility; and the form of this intuition can exist à priori in

our faculty of representation, without being anything else but the mode

in which the subject is affected. But the conjunction (conjunctio) of a

manifold in intuition never can be given us by the senses; it cannot

therefore be contained in the pure form of sensuous intuition, for it

is a spontaneous act of the faculty of representation. And as we must,

to distinguish it from sensibility, entitle this faculty understanding;

so all conjunction whether conscious or unconscious, be it of the

manifold in intuition, sensuous or non-sensuous, or of several

conceptions—is an act of the understanding. To this act we shall give

the general appellation of synthesis, thereby to indicate, at the same

time, that we cannot represent anything as conjoined in the object

without having previously conjoined it ourselves. Of all mental

notions, that of conjunction is the only one which cannot be given

through objects, but can be originated only by the subject itself,

because it is an act of its purely spontaneous activity. The reader

will easily enough perceive that the possibility of conjunction must be

grounded in the very nature of this act, and that it must be equally

valid for all conjunction, and that analysis, which appears to be its

contrary, must, nevertheless, always presuppose it; for where the

understanding has not previously conjoined, it cannot dissect or

analyse, because only as conjoined by it, must that which is to be

analysed have been given to our faculty of representation.

But the conception of conjunction includes, besides the conception of

the manifold and of the synthesis of it, that of the unity of it also.

Conjunction is the representation of the synthetical unity of the

manifold.[15] This idea of unity, therefore, cannot arise out of that

of conjunction; much rather does that idea, by combining itself with

the representation of the manifold, render the conception of

conjunction possible. This unity, which à priori precedes all

conceptions of conjunction, is not the category of unity (§ 6); for all

the categories are based upon logical functions of judgement, and in

these functions we already have conjunction, and consequently unity of

given conceptions. It is therefore evident that the category of unity

presupposes conjunction. We must therefore look still higher for this

unity (as qualitative, § 8), in that, namely, which contains the ground

of the unity of diverse conceptions in judgements, the ground,

consequently, of the possibility of the existence of the understanding,

even in regard to its logical use.

[15] Whether the representations are in themselves identical, and

consequently whether one can be thought analytically by means of and

through the other, is a question which we need not at present

consider. Our Consciousness of the one, when we speak of the manifold,

is always distinguishable from our consciousness of the other; and it

is only respecting the synthesis of this (possible) consciousness that

we here treat.

Of the Originally Synthetical Unity of Apperception § 12

The “I think” must accompany all my representations, for otherwise

something would be represented in me which could not be thought; in

other words, the representation would either be impossible, or at least

be, in relation to me, nothing. That representation which can be given

previously to all thought is called intuition. All the diversity or

manifold content of intuition, has, therefore, a necessary relation to

the “I think,” in the subject in which this diversity is found. But

this representation, “I think,” is an act of spontaneity; that is to

say, it cannot be regarded as belonging to mere sensibility. I call it

pure apperception, in order to distinguish it from empirical; or

primitive apperception, because it is self-consciousness which, whilst

it gives birth to the representation “I think,” must necessarily be

capable of accompanying all our representations. It is in all acts of

consciousness one and the same, and unaccompanied by it, no

representation can exist for me. The unity of this apperception I call

the transcendental unity of self-consciousness, in order to indicate

the possibility of à priori cognition arising from it. For the manifold

representations which are given in an intuition would not all of them

be my representations, if they did not all belong to one

self-consciousness, that is, as my representations (even although I am

not conscious of them as such), they must conform to the condition

under which alone they can exist together in a common

self-consciousness, because otherwise they would not all without

exception belong to me. From this primitive conjunction follow many

important results.

For example, this universal identity of the apperception of the

manifold given in intuition contains a synthesis of representations and

is possible only by means of the consciousness of this synthesis. For

the empirical consciousness which accompanies different representations

is in itself fragmentary and disunited, and without relation to the

identity of the subject. This relation, then, does not exist because I

accompany every representation with consciousness, but because I join

one representation to another, and am conscious of the synthesis of

them. Consequently, only because I can connect a variety of given

representations in one consciousness, is it possible that I can

represent to myself the identity of consciousness in these

representations; in other words, the analytical unity of apperception

is possible only under the presupposition of a synthetical unity.[16]

The thought, “These representations given in intuition belong all of

them to me,” is accordingly just the same as, “I unite them in one

self-consciousness, or can at least so unite them”; and although this

thought is not itself the consciousness of the synthesis of

representations, it presupposes the possibility of it; that is to say,

for the reason alone that I can comprehend the variety of my

representations in one consciousness, do I call them my

representations, for otherwise I must have as many-coloured and various

a self as are the representations of which I am conscious. Synthetical

unity of the manifold in intuitions, as given à priori, is therefore

the foundation of the identity of apperception itself, which antecedes

à priori all determinate thought. But the conjunction of

representations into a conception is not to be found in objects

themselves, nor can it be, as it were, borrowed from them and taken up

into the understanding by perception, but it is on the contrary an

operation of the understanding itself, which is nothing more than the

faculty of conjoining à priori and of bringing the variety of given

representations under the unity of apperception. This principle is the

highest in all human cognition.

[16] All general conceptions—as such—depend, for their existence, on

the analytical unity of consciousness. For example, when I think of

red in general, I thereby think to myself a property which (as a

characteristic mark) can be discovered somewhere, or can be united

with other representations; consequently, it is only by means of a

forethought possible synthetical unity that I can think to myself the

analytical. A representation which is cogitated as common to different

representations, is regarded as belonging to such as, besides this

common representation, contain something different; consequently it

must be previously thought in synthetical unity with other although

only possible representations, before I can think in it the analytical

unity of consciousness which makes it a conceptas communis. And thus

the synthetical unity of apperception is the highest point with which

we must connect every operation of the understanding, even the whole

of logic, and after it our transcendental philosophy; indeed, this

faculty is the understanding itself.

This fundamental principle of the necessary unity of apperception is

indeed an identical, and therefore analytical, proposition; but it

nevertheless explains the necessity for a synthesis of the manifold

given in an intuition, without which the identity of self-consciousness

would be incogitable. For the ego, as a simple representation, presents

us with no manifold content; only in intuition, which is quite

different from the representation ego, can it be given us, and by means

of conjunction it is cogitated in one self-consciousness. An

understanding, in which all the manifold should be given by means of

consciousness itself, would be intuitive; our understanding can only

think and must look for its intuition to sense. I am, therefore,

conscious of my identical self, in relation to all the variety of

representations given to me in an intuition, because I call all of them

my representations. In other words, I am conscious myself of a

necessary à priori synthesis of my representations, which is called the

original synthetical unity of apperception, under which rank all the

representations presented to me, but that only by means of a synthesis.

The Principle of the Synthetical Unity of Apperception is the highest

Principle of all exercise of the Understanding § 13

The supreme principle of the possibility of all intuition in relation

to sensibility was, according to our transcendental æsthetic, that all

the manifold in intuition be subject to the formal conditions of space

and time. The supreme principle of the possibility of it in relation to

the understanding is that all the manifold in it be subject to

conditions of the originally synthetical unity or apperception.[17] To

the former of these two principles are subject all the various

representations of intuition, in so far as they are given to us; to the

latter, in so far as they must be capable of conjunction in one

consciousness; for without this nothing can be thought or cognized,

because the given representations would not have in common the act Of

the apperception “I think” and therefore could not be connected in one

self-consciousness.

[17] Space and time, and all portions thereof, are intuitions;

consequently are, with a manifold for their content, single

representations. (See the Transcendental Æsthetic.) Consequently, they

are not pure conceptions, by means of which the same consciousness is

found in a great number of representations; but, on the contrary, they

are many representations contained in one, the consciousness of which

is, so to speak, compounded. The unity of consciousness is

nevertheless synthetical and, therefore, primitive. From this peculiar

character of consciousness follow many important consequences. (See §

21.)

Understanding is, to speak generally, the faculty Of cognitions. These

consist in the determined relation of given representation to an

object. But an object is that, in the conception of which the manifold

in a given intuition is united. Now all union of representations

requires unity of consciousness in the synthesis of them. Consequently,

it is the unity of consciousness alone that constitutes the possibility

of representations relating to an object, and therefore of their

objective validity, and of their becoming cognitions, and consequently,

the possibility of the existence of the understanding itself.

The first pure cognition of understanding, then, upon which is founded

all its other exercise, and which is at the same time perfectly

independent of all conditions of mere sensuous intuition, is the

principle of the original synthetical unity of apperception. Thus the

mere form of external sensuous intuition, namely, space, affords us,

per se, no cognition; it merely contributes the manifold in à priori

intuition to a possible cognition. But, in order to cognize something

in space (for example, a line), I must draw it, and thus produce

synthetically a determined conjunction of the given manifold, so that

the unity of this act is at the same time the unity of consciousness

(in the conception of a line), and by this means alone is an object (a

determinate space) cognized. The synthetical unity of consciousness is,

therefore, an objective condition of all cognition, which I do not

merely require in order to cognize an object, but to which every

intuition must necessarily be subject, in order to become an object for

me; because in any other way, and without this synthesis, the manifold

in intuition could not be united in one consciousness.

This proposition is, as already said, itself analytical, although it

constitutes the synthetical unity, the condition of all thought; for it

states nothing more than that all my representations in any given

intuition must be subject to the condition which alone enables me to

connect them, as my representation with the identical self, and so to

unite them synthetically in one apperception, by means of the general

expression, “I think.”

But this principle is not to be regarded as a principle for every

possible understanding, but only for the understanding by means of

whose pure apperception in the thought I am, no manifold content is

given. The understanding or mind which contained the manifold in

intuition, in and through the act itself of its own self-consciousness,

in other words, an understanding by and in the representation of which

the objects of the representation should at the same time exist, would

not require a special act of synthesis of the manifold as the condition

of the unity of its consciousness, an act of which the human

understanding, which thinks only and cannot intuite, has absolute need.

But this principle is the first principle of all the operations of our

understanding, so that we cannot form the least conception of any other

possible understanding, either of one such as should be itself

intuition, or possess a sensuous intuition, but with forms different

from those of space and time.

What Objective Unity of Self-consciousness is § 14

It is by means of the transcendental unity of apperception that all the

manifold, given in an intuition is united into a conception of the

object. On this account it is called objective, and must be

distinguished from the subjective unity of consciousness, which is a

determination of the internal sense, by means of which the said

manifold in intuition is given empirically to be so united. Whether I

can be empirically conscious of the manifold as coexistent or as

successive, depends upon circumstances, or empirical conditions. Hence

the empirical unity of consciousness by means of association of

representations, itself relates to a phenomenal world and is wholly

contingent. On the contrary, the pure form of intuition in time, merely

as an intuition, which contains a given manifold, is subject to the

original unity of consciousness, and that solely by means of the

necessary relation of the manifold in intuition to the “I think,”

consequently by means of the pure synthesis of the understanding, which

lies à priori at the foundation of all empirical synthesis. The

transcendental unity of apperception is alone objectively valid; the

empirical which we do not consider in this essay, and which is merely a

unity deduced from the former under given conditions in concreto,

possesses only subjective validity. One person connects the notion

conveyed in a word with one thing, another with another thing; and the

unity of consciousness in that which is empirical, is, in relation to

that which is given by experience, not necessarily and universally

valid.

The Logical Form of all Judgements consists in the Objective Unity of

Apperception of the Conceptions contained therein § 15

I could never satisfy myself with the definition which logicians give

of a judgement. It is, according to them, the representation of a

relation between two conceptions. I shall not dwell here on the

faultiness of this definition, in that it suits only for categorical

and not for hypothetical or disjunctive judgements, these latter

containing a relation not of conceptions but of judgements themselves—a

blunder from which many evil results have followed.[18] It is more

important for our present purpose to observe, that this definition does

not determine in what the said relation consists.

[18] The tedious doctrine of the four syllogistic figures concerns

only categorical syllogisms; and although it is nothing more than

an artifice by surreptitiously introducing immediate conclusions

(consequentiae immediatae) among the premises of a pure syllogism,

to give rise to an appearance of more modes of drawing a conclusion

than that in the first figure, the artifice would not have had much

success, had not its authors succeeded in bringing categorical

judgements into exclusive respect, as those to which all others must

be referred—a doctrine, however, which, according to § 5, is utterly

false.

But if I investigate more closely the relation of given cognitions in

every judgement, and distinguish it, as belonging to the understanding,

from the relation which is produced according to laws of the

reproductive imagination (which has only subjective validity), I find

that judgement is nothing but the mode of bringing given cognitions

under the objective unit of apperception. This is plain from our use of

the term of relation is in judgements, in order to distinguish the

objective unity of given representations from the subjective unity. For

this term indicates the relation of these representations to the

original apperception, and also their necessary unity, even although

the judgement is empirical, therefore contingent, as in the judgement:

“All bodies are heavy.” I do not mean by this, that these

representations do necessarily belong to each other in empirical

intuition, but that by means of the necessary unity of appreciation

they belong to each other in the synthesis of intuitions, that is to

say, they belong to each other according to principles of the objective

determination of all our representations, in so far as cognition can

arise from them, these principles being all deduced from the main

principle of the transcendental unity of apperception. In this way

alone can there arise from this relation a judgement, that is, a

relation which has objective validity, and is perfectly distinct from

that relation of the very same representations which has only

subjective validity—a relation, to wit, which is produced according to

laws of association. According to these laws, I could only say: “When I

hold in my hand or carry a body, I feel an impression of weight”; but I

could not say: “It, the body, is heavy”; for this is tantamount to

saying both these representations are conjoined in the object, that is,

without distinction as to the condition of the subject, and do not

merely stand together in my perception, however frequently the

perceptive act may be repeated.

All Sensuous Intuitions are subject to the Categories, as Conditions

under which alone the manifold Content of them can be united in one

Consciousness § 16

The manifold content given in a sensuous intuition comes necessarily

under the original synthetical unity of apperception, because thereby

alone is the unity of intuition possible (§ 13). But that act of the

understanding, by which the manifold content of given representations

(whether intuitions or conceptions) is brought under one apperception,

is the logical function of judgements (§ 15). All the manifold,

therefore, in so far as it is given in one empirical intuition, is

determined in relation to one of the logical functions of judgement, by

means of which it is brought into union in one consciousness. Now the

categories are nothing else than these functions of judgement so far as

the manifold in a given intuition is determined in relation to them (§

9). Consequently, the manifold in a given intuition is necessarily

subject to the categories of the understanding.

Observation § 17

The manifold in an intuition, which I call mine, is represented by

means of the synthesis of the understanding, as belonging to the

necessary unity of self-consciousness, and this takes place by means of

the category.[19] The category indicates accordingly that the empirical

consciousness of a given manifold in an intuition is subject to a pure

self-consciousness à priori, in the same manner as an empirical

intuition is subject to a pure sensuous intuition, which is also à

priori. In the above proposition, then, lies the beginning of a

deduction of the pure conceptions of the understanding. Now, as the

categories have their origin in the understanding alone, independently

of sensibility, I must in my deduction make abstraction of the mode in

which the manifold of an empirical intuition is given, in order to fix

my attention exclusively on the unity which is brought by the

understanding into the intuition by means of the category. In what

follows (§ 22), it will be shown, from the mode in which the empirical

intuition is given in the faculty of sensibility, that the unity which

belongs to it is no other than that which the category (according to §

16) imposes on the manifold in a given intuition, and thus, its à

priori validity in regard to all objects of sense being established,

the purpose of our deduction will be fully attained.

[19] The proof of this rests on the represented unity of intuition, by

means of which an object is given, and which always includes in itself

a synthesis of the manifold to be intuited, and also the relation of

this latter to unity of apperception.

But there is one thing in the above demonstration of which I could not

make abstraction, namely, that the manifold to be intuited must be

given previously to the synthesis of the understanding, and

independently of it. How this takes place remains here undetermined.

For if I cogitate an understanding which was itself intuitive (as, for

example, a divine understanding which should not represent given

objects, but by whose representation the objects themselves should be

given or produced), the categories would possess no significance in

relation to such a faculty of cognition. They are merely rules for an

understanding, whose whole power consists in thought, that is, in the

act of submitting the synthesis of the manifold which is presented to

it in intuition from a very different quarter, to the unity of

apperception; a faculty, therefore, which cognizes nothing per se, but

only connects and arranges the material of cognition, the intuition,

namely, which must be presented to it by means of the object. But to

show reasons for this peculiar character of our understandings, that it

produces unity of apperception à priori only by means of categories,

and a certain kind and number thereof, is as impossible as to explain

why we are endowed with precisely so many functions of judgement and no

more, or why time and space are the only forms of our intuition.

In Cognition, its Application to Objects of Experience is the only

legitimate use of the Category § 18

To think an object and to cognize an object are by no means the same

thing. In cognition there are two elements: firstly, the conception,

whereby an object is cogitated (the category); and, secondly, the

intuition, whereby the object is given. For supposing that to the

conception a corresponding intuition could not be given, it would still

be a thought as regards its form, but without any object, and no

cognition of anything would be possible by means of it, inasmuch as, so

far as I knew, there existed and could exist nothing to which my

thought could be applied. Now all intuition possible to us is sensuous;

consequently, our thought of an object by means of a pure conception of

the understanding, can become cognition for us only in so far as this

conception is applied to objects of the senses. Sensuous intuition is

either pure intuition (space and time) or empirical intuition—of that

which is immediately represented in space and time by means of

sensation as real. Through the determination of pure intuition we

obtain à priori cognitions of objects, as in mathematics, but only as

regards their form as phenomena; whether there can exist things which

must be intuited in this form is not thereby established. All

mathematical conceptions, therefore, are not per se cognition, except

in so far as we presuppose that there exist things which can only be

represented conformably to the form of our pure sensuous intuition. But

things in space and time are given only in so far as they are

perceptions (representations accompanied with sensation), therefore

only by empirical representation. Consequently the pure conceptions of

the understanding, even when they are applied to intuitions à priori

(as in mathematics), produce cognition only in so far as these (and

therefore the conceptions of the understanding by means of them) can be

applied to empirical intuitions. Consequently the categories do not,

even by means of pure intuition afford us any cognition of things; they

can only do so in so far as they can be applied to empirical intuition.

That is to say, the categories serve only to render empirical cognition

possible. But this is what we call experience. Consequently, in

cognition, their application to objects of experience is the only

legitimate use of the categories.

§ 19

The foregoing proposition is of the utmost importance, for it

determines the limits of the exercise of the pure conceptions of the

understanding in regard to objects, just as transcendental æsthetic

determined the limits of the exercise of the pure form of our sensuous

intuition. Space and time, as conditions of the possibility of the

presentation of objects to us, are valid no further than for objects of

sense, consequently, only for experience. Beyond these limits they

represent to us nothing, for they belong only to sense, and have no

reality apart from it. The pure conceptions of the understanding are

free from this limitation, and extend to objects of intuition in

general, be the intuition like or unlike to ours, provided only it be

sensuous, and not intellectual. But this extension of conceptions

beyond the range of our intuition is of no advantage; for they are then

mere empty conceptions of objects, as to the possibility or

impossibility of the existence of which they furnish us with no means

of discovery. They are mere forms of thought, without objective

reality, because we have no intuition to which the synthetical unity of

apperception, which alone the categories contain, could be applied, for

the purpose of determining an object. Our sensuous and empirical

intuition can alone give them significance and meaning.

If, then, we suppose an object of a non-sensuous intuition to be given

we can in that case represent it by all those predicates which are

implied in the presupposition that nothing appertaining to sensuous

intuition belongs to it; for example, that it is not extended, or in

space; that its duration is not time; that in it no change (the effect

of the determinations in time) is to be met with, and so on. But it is

no proper knowledge if I merely indicate what the intuition of the

object is not, without being able to say what is contained in it, for I

have not shown the possibility of an object to which my pure conception

of understanding could be applicable, because I have not been able to

furnish any intuition corresponding to it, but am only able to say that

our intuition is not valid for it. But the most important point is

this, that to a something of this kind not one category can be found

applicable. Take, for example, the conception of substance, that is,

something that can exist as subject, but never as mere predicate; in

regard to this conception I am quite ignorant whether there can really

be anything to correspond to such a determination of thought, if

empirical intuition did not afford me the occasion for its application.

But of this more in the sequel.

Of the Application of the Categories to Objects of the Senses in

general § 20

The pure conceptions of the understanding apply to objects of intuition

in general, through the understanding alone, whether the intuition be

our own or some other, provided only it be sensuous, but are, for this

very reason, mere forms of thought, by means of which alone no

determined object can be cognized. The synthesis or conjunction of the

manifold in these conceptions relates, we have said, only to the unity

of apperception, and is for this reason the ground of the possibility

of à priori cognition, in so far as this cognition is dependent on the

understanding. This synthesis is, therefore, not merely transcendental,

but also purely intellectual. But because a certain form of sensuous

intuition exists in the mind à priori which rests on the receptivity of

the representative faculty (sensibility), the understanding, as a

spontaneity, is able to determine the internal sense by means of the

diversity of given representations, conformably to the synthetical

unity of apperception, and thus to cogitate the synthetical unity of

the apperception of the manifold of sensuous intuition à priori, as the

condition to which must necessarily be submitted all objects of human

intuition. And in this manner the categories as mere forms of thought

receive objective reality, that is, application to objects which are

given to us in intuition, but that only as phenomena, for it is only of

phenomena that we are capable of à priori intuition.

This synthesis of the manifold of sensuous intuition, which is possible

and necessary à priori, may be called figurative (synthesis speciosa),

in contradistinction to that which is cogitated in the mere category in

regard to the manifold of an intuition in general, and is called

connection or conjunction of the understanding (synthesis

intellectualis). Both are transcendental, not merely because they

themselves precede à priori all experience, but also because they form

the basis for the possibility of other cognition à priori.

But the figurative synthesis, when it has relation only to the

originally synthetical unity of apperception, that is to the

transcendental unity cogitated in the categories, must, to be

distinguished from the purely intellectual conjunction, be entitled the

transcendental synthesis of imagination. Imagination is the faculty of

representing an object even without its presence in intuition. Now, as

all our intuition is sensuous, imagination, by reason of the subjective

condition under which alone it can give a corresponding intuition to

the conceptions of the understanding, belongs to sensibility. But in so

far as the synthesis of the imagination is an act of spontaneity, which

is determinative, and not, like sense, merely determinable, and which

is consequently able to determine sense à priori, according to its

form, conformably to the unity of apperception, in so far is the

imagination a faculty of determining sensibility à priori, and its

synthesis of intuitions according to the categories must be the

transcendental synthesis of the imagination. It is an operation of the

understanding on sensibility, and the first application of the

understanding to objects of possible intuition, and at the same time

the basis for the exercise of the other functions of that faculty. As

figurative, it is distinguished from the merely intellectual synthesis,

which is produced by the understanding alone, without the aid of

imagination. Now, in so far as imagination is spontaneity, I sometimes

call it also the productive imagination, and distinguish it from the

reproductive, the synthesis of which is subject entirely to empirical

laws, those of association, namely, and which, therefore, contributes

nothing to the explanation of the possibility of à priori cognition,

and for this reason belongs not to transcendental philosophy, but to

psychology.

We have now arrived at the proper place for explaining the paradox

which must have struck every one in our exposition of the internal

sense (§ 6), namely—how this sense represents us to our own

consciousness, only as we appear to ourselves, not as we are in

ourselves, because, to wit, we intuite ourselves only as we are

inwardly affected. Now this appears to be contradictory, inasmuch as we

thus stand in a passive relation to ourselves; and therefore in the

systems of psychology, the internal sense is commonly held to be one

with the faculty of apperception, while we, on the contrary, carefully

distinguish them.

That which determines the internal sense is the understanding, and its

original power of conjoining the manifold of intuition, that is, of

bringing this under an apperception (upon which rests the possibility

of the understanding itself). Now, as the human understanding is not in

itself a faculty of intuition, and is unable to exercise such a power,

in order to conjoin, as it were, the manifold of its own intuition, the

synthesis of understanding is, considered per se, nothing but the unity

of action, of which, as such, it is self-conscious, even apart from

sensibility, by which, moreover, it is able to determine our internal

sense in respect of the manifold which may be presented to it according

to the form of sensuous intuition. Thus, under the name of a

transcendental synthesis of imagination, the understanding exercises an

activity upon the passive subject, whose faculty it is; and so we are

right in saying that the internal sense is affected thereby.

Apperception and its synthetical unity are by no means one and the same

with the internal sense. The former, as the source of all our

synthetical conjunction, applies, under the name of the categories, to

the manifold of intuition in general, prior to all sensuous intuition

of objects. The internal sense, on the contrary, contains merely the

form of intuition, but without any synthetical conjunction of the

manifold therein, and consequently does not contain any determined

intuition, which is possible only through consciousness of the

determination of the manifold by the transcendental act of the

imagination (synthetical influence of the understanding on the internal

sense), which I have named figurative synthesis.

This we can indeed always perceive in ourselves. We cannot cogitate a

geometrical line without drawing it in thought, nor a circle without

describing it, nor represent the three dimensions of space without

drawing three lines from the same point perpendicular to one another.

We cannot even cogitate time, unless, in drawing a straight line (which

is to serve as the external figurative representation of time), we fix

our attention on the act of the synthesis of the manifold, whereby we

determine successively the internal sense, and thus attend also to the

succession of this determination. Motion as an act of the subject (not

as a determination of an object),[20] consequently the synthesis of the

manifold in space, if we make abstraction of space and attend merely to

the act by which we determine the internal sense according to its form,

is that which produces the conception of succession. The understanding,

therefore, does by no means find in the internal sense any such

synthesis of the manifold, but produces it, in that it affects this

sense. At the same time, how “I who think” is distinct from the “i”

which intuites itself (other modes of intuition being cogitable as at

least possible), and yet one and the same with this latter as the same

subject; how, therefore, I am able to say: “I, as an intelligence and

thinking subject, cognize myself as an object thought, so far as I am,

moreover, given to myself in intuition—only, like other phenomena, not

as I am in myself, and as considered by the understanding, but merely

as I appear”—is a question that has in it neither more nor less

difficulty than the question—“How can I be an object to myself?” or

this—“How I can be an object of my own intuition and internal

perceptions?” But that such must be the fact, if we admit that space is

merely a pure form of the phenomena of external sense, can be clearly

proved by the consideration that we cannot represent time, which is not

an object of external intuition, in any other way than under the image

of a line, which we draw in thought, a mode of representation without

which we could not cognize the unity of its dimension, and also that we

are necessitated to take our determination of periods of time, or of

points of time, for all our internal perceptions from the changes which

we perceive in outward things. It follows that we must arrange the

determinations of the internal sense, as phenomena in time, exactly in

the same manner as we arrange those of the external senses in space.

And consequently, if we grant, respecting this latter, that by means of

them we know objects only in so far as we are affected externally, we

must also confess, with regard to the internal sense, that by means of

it we intuite ourselves only as we are internally affected by

ourselves; in other words, as regards internal intuition, we cognize

our own subject only as phenomenon, and not as it is in itself.[21]

[20] Motion of an object in space does not belong to a pure science,

consequently not to geometry; because, that a thing is movable cannot

be known à priori, but only from experience. But motion, considered as

the description of a space, is a pure act of the successive synthesis

of the manifold in external intuition by means of productive

imagination, and belongs not only to geometry, but even to

transcendental philosophy.

[21] I do not see why so much difficulty should be found in admitting

that our internal sense is affected by ourselves. Every act of

attention exemplifies it. In such an act the understanding determines

the internal sense by the synthetical conjunction which it cogitates,

conformably to the internal intuition which corresponds to the

manifold in the synthesis of the understanding. How much the mind is

usually affected thereby every one will be able to perceive in

himself.

§ 21

On the other hand, in the transcendental synthesis of the manifold

content of representations, consequently in the synthetical unity of

apperception, I am conscious of myself, not as I appear to myself, nor

as I am in myself, but only that “I am.” This representation is a

thought, not an intuition. Now, as in order to cognize ourselves, in

addition to the act of thinking, which subjects the manifold of every

possible intuition to the unity of apperception, there is necessary a

determinate mode of intuition, whereby this manifold is given; although

my own existence is certainly not mere phenomenon (much less mere

illusion), the determination of my existence[22] Can only take place

conformably to the form of the internal sense, according to the

particular mode in which the manifold which I conjoin is given in

internal intuition, and I have therefore no knowledge of myself as I

am, but merely as I appear to myself. The consciousness of self is thus

very far from a knowledge of self, in which I do not use the

categories, whereby I cogitate an object, by means of the conjunction

of the manifold in one apperception. In the same way as I require, for

the sake of the cognition of an object distinct from myself, not only

the thought of an object in general (in the category), but also an

intuition by which to determine that general conception, in the same

way do I require, in order to the cognition of myself, not only the

consciousness of myself or the thought that I think myself, but in

addition an intuition of the manifold in myself, by which to determine

this thought. It is true that I exist as an intelligence which is

conscious only of its faculty of conjunction or synthesis, but

subjected in relation to the manifold which this intelligence has to

conjoin to a limitative conjunction called the internal sense. My

intelligence (that is, I) can render that conjunction or synthesis

perceptible only according to the relations of time, which are quite

beyond the proper sphere of the conceptions of the understanding and

consequently cognize itself in respect to an intuition (which cannot

possibly be intellectual, nor given by the understanding), only as it

appears to itself, and not as it would cognize itself, if its intuition

were intellectual.

[22] The “I think” expresses the act of determining my own existence.

My existence is thus already given by the act of consciousness; but

the mode in which I must determine my existence, that is, the mode in

which I must place the manifold belonging to my existence, is not

thereby given. For this purpose intuition of self is required, and

this intuition possesses a form given à priori, namely, time, which is

sensuous, and belongs to our receptivity of the determinable. Now, as

I do not possess another intuition of self which gives the determining

in me (of the spontaneity of which I am conscious), prior to the act

of determination, in the same manner as time gives the determinable,

it is clear that I am unable to determine my own existence as that of

a spontaneous being, but I am only able to represent to myself the

spontaneity of my thought, that is, of my determination, and my

existence remains ever determinable in a purely sensuous manner, that

is to say, like the existence of a phenomenon. But it is because of

this spontaneity that I call myself an intelligence.

Transcendental Deduction of the universally possible employment in

experience of the Pure Conceptions of the Understanding § 22

In the metaphysical deduction, the à priori origin of categories was

proved by their complete accordance with the general logical of

thought; in the transcendental deduction was exhibited the possibility

of the categories as à priori cognitions of objects of an intuition in

general (§ 16 and 17).At present we are about to explain the

possibility of cognizing, à priori, by means of the categories, all

objects which can possibly be presented to our senses, not, indeed,

according to the form of their intuition, but according to the laws of

their conjunction or synthesis, and thus, as it were, of prescribing

laws to nature and even of rendering nature possible. For if the

categories were inadequate to this task, it would not be evident to us

why everything that is presented to our senses must be subject to those

laws which have an à priori origin in the understanding itself.

I premise that by the term synthesis of apprehension I understand the

combination of the manifold in an empirical intuition, whereby

perception, that is, empirical consciousness of the intuition (as

phenomenon), is possible.

We have à priori forms of the external and internal sensuous intuition

in the representations of space and time, and to these must the

synthesis of apprehension of the manifold in a phenomenon be always

comformable, because the synthesis itself can only take place according

to these forms. But space and time are not merely forms of sensuous

intuition, but intuitions themselves (which contain a manifold), and

therefore contain à priori the determination of the unity of this

manifold.[23] (See the Transcendent Æsthetic.) Therefore is unity of

the synthesis of the manifold without or within us, consequently also a

conjunction to which all that is to be represented as determined in

space or time must correspond, given à priori along with (not in) these

intuitions, as the condition of the synthesis of all apprehension of

them. But this synthetical unity can be no other than that of the

conjunction of the manifold of a given intuition in general, in a

primitive act of consciousness, according to the categories, but

applied to our sensuous intuition. Consequently all synthesis, whereby

alone is even perception possible, is subject to the categories. And,

as experience is cognition by means of conjoined perceptions, the

categories are conditions of the possibility of experience and are

therefore valid à priori for all objects of experience.

[23] Space represented as an object (as geometry really requires it to

be) contains more than the mere form of the intuition; namely, a

combination of the manifold given according to the form of sensibility

into a representation that can be intuited; so that the form of the

intuition gives us merely the manifold, but the formal intuition gives

unity of representation. In the æsthetic, I regarded this unity as

belonging entirely to sensibility, for the purpose of indicating that

it antecedes all conceptions, although it presupposes a synthesis

which does not belong to sense, through which alone, however, all our

conceptions of space and time are possible. For as by means of this

unity alone (the understanding determining the sensibility) space and

time are given as intuitions, it follows that the unity of this

intuition à priori belongs to space and time, and not to the

conception of the understanding (§ 20).

When, then, for example, I make the empirical intuition of a house by

apprehension of the manifold contained therein into a perception, the

necessary unity of space and of my external sensuous intuition lies at

the foundation of this act, and I, as it were, draw the form of the

house conformably to this synthetical unity of the manifold in space.

But this very synthetical unity remains, even when I abstract the form

of space, and has its seat in the understanding, and is in fact the

category of the synthesis of the homogeneous in an intuition; that is

to say, the category of quantity, to which the aforesaid synthesis of

apprehension, that is, the perception, must be completely

conformable.[24]

[24] In this manner it is proved, that the synthesis of apprehension,

which is empirical, must necessarily be conformable to the synthesis

of apperception, which is intellectual, and contained à priori in the

category. It is one and the same spontaneity which at one time, under

the name of imagination, at another under that of understanding,

produces conjunction in the manifold of intuition.

To take another example, when I perceive the freezing of water, I

apprehend two states (fluidity and solidity), which, as such, stand

toward each other mutually in a relation of time. But in the time,

which I place as an internal intuition, at the foundation of this

phenomenon, I represent to myself synthetical unity of the manifold,

without which the aforesaid relation could not be given in an intuition

as determined (in regard to the succession of time). Now this

synthetical unity, as the à priori condition under which I conjoin the

manifold of an intuition, is, if I make abstraction of the permanent

form of my internal intuition (that is to say, of time), the category

of cause, by means of which, when applied to my sensibility, I

determine everything that occurs according to relations of time.

Consequently apprehension in such an event, and the event itself, as

far as regards the possibility of its perception, stands under the

conception of the relation of cause and effect: and so in all other

cases.

Categories are conceptions which prescribe laws à priori to phenomena,

consequently to nature as the complex of all phenomena (natura

materialiter spectata). And now the question arises—inasmuch as these

categories are not derived from nature, and do not regulate themselves

according to her as their model (for in that case they would be

empirical)—how it is conceivable that nature must regulate herself

according to them, in other words, how the categories can determine à

priori the synthesis of the manifold of nature, and yet not derive

their origin from her. The following is the solution of this enigma.

It is not in the least more difficult to conceive how the laws of the

phenomena of nature must harmonize with the understanding and with its

à priori form—that is, its faculty of conjoining the manifold—than it

is to understand how the phenomena themselves must correspond with the

à priori form of our sensuous intuition. For laws do not exist in the

phenomena any more than the phenomena exist as things in themselves.

Laws do not exist except by relation to the subject in which the

phenomena inhere, in so far as it possesses understanding, just as

phenomena have no existence except by relation to the same existing

subject in so far as it has senses. To things as things in themselves,

conformability to law must necessarily belong independently of an

understanding to cognize them. But phenomena are only representations

of things which are utterly unknown in respect to what they are in

themselves. But as mere representations, they stand under no law of

conjunction except that which the conjoining faculty prescribes. Now

that which conjoins the manifold of sensuous intuition is imagination,

a mental act to which understanding contributes unity of intellectual

synthesis, and sensibility, manifoldness of apprehension. Now as all

possible perception depends on the synthesis of apprehension, and this

empirical synthesis itself on the transcendental, consequently on the

categories, it is evident that all possible perceptions, and therefore

everything that can attain to empirical consciousness, that is, all

phenomena of nature, must, as regards their conjunction, be subject to

the categories. And nature (considered merely as nature in general) is

dependent on them, as the original ground of her necessary

conformability to law (as natura formaliter spectata). But the pure

faculty (of the understanding) of prescribing laws à priori to

phenomena by means of mere categories, is not competent to enounce

other or more laws than those on which a nature in general, as a

conformability to law of phenomena of space and time, depends.

Particular laws, inasmuch as they concern empirically determined

phenomena, cannot be entirely deduced from pure laws, although they all

stand under them. Experience must be superadded in order to know these

particular laws; but in regard to experience in general, and everything

that can be cognized as an object thereof, these à priori laws are our

only rule and guide.

Result of this Deduction of the Conceptions of the Understanding § 23

We cannot think any object except by means of the categories; we cannot

cognize any thought except by means of intuitions corresponding to

these conceptions. Now all our intuitions are sensuous, and our

cognition, in so far as the object of it is given, is empirical. But

empirical cognition is experience; consequently no à priori cognition

is possible for us, except of objects of possible experience.[25]

[25] Lest my readers should stumble at this assertion, and the

conclusions that may be too rashly drawn from it, I must remind them

that the categories in the act of thought are by no means limited by

the conditions of our sensuous intuition, but have an unbounded sphere

of action. It is only the cognition of the object of thought, the

determining of the object, which requires intuition. In the absence of

intuition, our thought of an object may still have true and useful

consequences in regard to the exercise of reason by the subject. But

as this exercise of reason is not always directed on the determination

of the object, in other words, on cognition thereof, but also on the

determination of the subject and its volition, I do not intend to

treat of it in this place.

But this cognition, which is limited to objects of experience, is not

for that reason derived entirely, from, experience, but—and this is

asserted of the pure intuitions and the pure conceptions of the

understanding—there are, unquestionably, elements of cognition, which

exist in the mind à priori. Now there are only two ways in which a

necessary harmony of experience with the conceptions of its objects can

be cogitated. Either experience makes these conceptions possible, or

the conceptions make experience possible. The former of these

statements will not hold good with respect to the categories (nor in

regard to pure sensuous intuition), for they are à priori conceptions,

and therefore independent of experience. The assertion of an empirical

origin would attribute to them a sort of generatio aequivoca.

Consequently, nothing remains but to adopt the second alternative

(which presents us with a system, as it were, of the epigenesis of pure

reason), namely, that on the part of the understanding the categories

do contain the grounds of the possibility of all experience. But with

respect to the questions how they make experience possible, and what

are the principles of the possibility thereof with which they present

us in their application to phenomena, the following section on the

transcendental exercise of the faculty of judgement will inform the

reader.

It is quite possible that someone may propose a species of

preformation-system of pure reason—a middle way between the two—to wit,

that the categories are neither innate and first à priori principles of

cognition, nor derived from experience, but are merely subjective

aptitudes for thought implanted in us contemporaneously with our

existence, which were so ordered and disposed by our Creator, that

their exercise perfectly harmonizes with the laws of nature which

regulate experience. Now, not to mention that with such an hypothesis

it is impossible to say at what point we must stop in the employment of

predetermined aptitudes, the fact that the categories would in this

case entirely lose that character of necessity which is essentially

involved in the very conception of them, is a conclusive objection to

it. The conception of cause, for example, which expresses the necessity

of an effect under a presupposed condition, would be false, if it

rested only upon such an arbitrary subjective necessity of uniting

certain empirical representations according to such a rule of relation.

I could not then say—“The effect is connected with its cause in the

object (that is, necessarily),” but only, “I am so constituted that I

can think this representation as so connected, and not otherwise.” Now

this is just what the sceptic wants. For in this case, all our

knowledge, depending on the supposed objective validity of our

judgement, is nothing but mere illusion; nor would there be wanting

people who would deny any such subjective necessity in respect to

themselves, though they must feel it. At all events, we could not

dispute with any one on that which merely depends on the manner in

which his subject is organized.

Short view of the above Deduction.

The foregoing deduction is an exposition of the pure conceptions of the

understanding (and with them of all theoretical à priori cognition), as

principles of the possibility of experience, but of experience as the

determination of all phenomena in space and time in general—of

experience, finally, from the principle of the original synthetical

unity of apperception, as the form of the understanding in relation to

time and space as original forms of sensibility.

I consider the division by paragraphs to be necessary only up to this

point, because we had to treat of the elementary conceptions. As we now

proceed to the exposition of the employment of these, I shall not

designate the chapters in this manner any further.

BOOK II. Analytic of Principles

General logic is constructed upon a plan which coincides exactly with

the division of the higher faculties of cognition. These are,

understanding, judgement, and reason. This science, accordingly, treats

in its analytic of conceptions, judgements, and conclusions in exact

correspondence with the functions and order of those mental powers

which we include generally under the generic denomination of

understanding.

As this merely formal logic makes abstraction of all content of

cognition, whether pure or empirical, and occupies itself with the mere

form of thought (discursive cognition), it must contain in its analytic

a canon for reason. For the form of reason has its law, which, without

taking into consideration the particular nature of the cognition about

which it is employed, can be discovered à priori, by the simple

analysis of the action of reason into its momenta.

Transcendental logic, limited as it is to a determinate content, that

of pure à priori cognitions, to wit, cannot imitate general logic in

this division. For it is evident that the transcendental employment of

reason is not objectively valid, and therefore does not belong to the

logic of truth (that is, to analytic), but as a logic of illusion,

occupies a particular department in the scholastic system under the

name of transcendental dialectic.

Understanding and judgement accordingly possess in transcendental logic

a canon of objectively valid, and therefore true exercise, and are

comprehended in the analytical department of that logic. But reason, in

her endeavours to arrive by à priori means at some true statement

concerning objects and to extend cognition beyond the bounds of

possible experience, is altogether dialectic, and her illusory

assertions cannot be constructed into a canon such as an analytic ought

to contain.

Accordingly, the analytic of principles will be merely a canon for the

faculty of judgement, for the instruction of this faculty in its

application to phenomena of the pure conceptions of the understanding,

which contain the necessary condition for the establishment of à priori

laws. On this account, although the subject of the following chapters

is the especial principles of understanding, I shall make use of the

term Doctrine of the faculty of judgement, in order to define more

particularly my present purpose.

INTRODUCTION. Of the Transcendental Faculty of judgement in General

If understanding in general be defined as the faculty of laws or rules,

the faculty of judgement may be termed the faculty of subsumption under

these rules; that is, of distinguishing whether this or that does or

does not stand under a given rule (casus datae legis). General logic

contains no directions or precepts for the faculty of judgement, nor

can it contain any such. For as it makes abstraction of all content of

cognition, no duty is left for it, except that of exposing analytically

the mere form of cognition in conceptions, judgements, and conclusions,

and of thereby establishing formal rules for all exercise of the

understanding. Now if this logic wished to give some general direction

how we should subsume under these rules, that is, how we should

distinguish whether this or that did or did not stand under them, this

again could not be done otherwise than by means of a rule. But this

rule, precisely because it is a rule, requires for itself direction

from the faculty of judgement. Thus, it is evident that the

understanding is capable of being instructed by rules, but that the

judgement is a peculiar talent, which does not, and cannot require

tuition, but only exercise. This faculty is therefore the specific

quality of the so-called mother wit, the want of which no scholastic

discipline can compensate.

For although education may furnish, and, as it were, engraft upon a

limited understanding rules borrowed from other minds, yet the power of

employing these rules correctly must belong to the pupil himself; and

no rule which we can prescribe to him with this purpose is, in the

absence or deficiency of this gift of nature, secure from misuse.[26] A

physician therefore, a judge or a statesman, may have in his head many

admirable pathological, juridical, or political rules, in a degree that

may enable him to be a profound teacher in his particular science, and

yet in the application of these rules he may very possibly

blunder—either because he is wanting in natural judgement (though not

in understanding) and, whilst he can comprehend the general in

abstracto, cannot distinguish whether a particular case in concreto

ought to rank under the former; or because his faculty of judgement has

not been sufficiently exercised by examples and real practice. Indeed,

the grand and only use of examples, is to sharpen the judgement. For as

regards the correctness and precision of the insight of the

understanding, examples are commonly injurious rather than otherwise,

because, as casus in terminis they seldom adequately fulfil the

conditions of the rule. Besides, they often weaken the power of our

understanding to apprehend rules or laws in their universality,

independently of particular circumstances of experience; and hence,

accustom us to employ them more as formulae than as principles.

Examples are thus the go-cart of the judgement, which he who is

naturally deficient in that faculty cannot afford to dispense with.

[26] Deficiency in judgement is properly that which is called

stupidity; and for such a failing we know no remedy. A dull or

narrow-minded person, to whom nothing is wanting but a proper degree

of understanding, may be improved by tuition, even so far as to

deserve the epithet of learned. But as such persons frequently labour

under a deficiency in the faculty of judgement, it is not uncommon to

find men extremely learned who in the application of their science

betray a lamentable degree this irremediable want.

But although general logic cannot give directions to the faculty of

judgement, the case is very different as regards transcendental logic,

insomuch that it appears to be the especial duty of the latter to

secure and direct, by means of determinate rules, the faculty of

judgement in the employment of the pure understanding. For, as a

doctrine, that is, as an endeavour to enlarge the sphere of the

understanding in regard to pure à priori cognitions, philosophy is

worse than useless, since from all the attempts hitherto made, little

or no ground has been gained. But, as a critique, in order to guard

against the mistakes of the faculty of judgement (lapsus judicii) in

the employment of the few pure conceptions of the understanding which

we possess, although its use is in this case purely negative,

philosophy is called upon to apply all its acuteness and penetration.

But transcendental philosophy has this peculiarity, that besides

indicating the rule, or rather the general condition for rules, which

is given in the pure conception of the understanding, it can, at the

same time, indicate à priori the case to which the rule must be

applied. The cause of the superiority which, in this respect,

transcendental philosophy possesses above all other sciences except

mathematics, lies in this: it treats of conceptions which must relate à

priori to their objects, whose objective validity consequently cannot

be demonstrated à posteriori, and is, at the same time, under the

obligation of presenting in general but sufficient tests, the

conditions under which objects can be given in harmony with those

conceptions; otherwise they would be mere logical forms, without

content, and not pure conceptions of the understanding.

Our transcendental doctrine of the faculty of judgement will contain

two chapters. The first will treat of the sensuous condition under

which alone pure conceptions of the understanding can be employed—that

is, of the schematism of the pure understanding. The second will treat

of those synthetical judgements which are derived à priori from pure

conceptions of the understanding under those conditions, and which lie

à priori at the foundation of all other cognitions, that is to say, it

will treat of the principles of the pure understanding.

TRANSCENDENTAL DOCTRINE OF THE FACULTY OF JUDGEMENT OR, ANALYTIC OF

PRINCIPLES

Chapter I. Of the Schematism at of the Pure Conceptions of the

Understanding

In all subsumptions of an object under a conception, the representation

of the object must be homogeneous with the conception; in other words,

the conception must contain that which is represented in the object to

be subsumed under it. For this is the meaning of the expression: “An

object is contained under a conception.” Thus the empirical conception

of a plate is homogeneous with the pure geometrical conception of a

circle, inasmuch as the roundness which is cogitated in the former is

intuited in the latter.

But pure conceptions of the understanding, when compared with empirical

intuitions, or even with sensuous intuitions in general, are quite

heterogeneous, and never can be discovered in any intuition. How then

is the subsumption of the latter under the former, and consequently the

application of the categories to phenomena, possible?—For it is

impossible to say, for example: “Causality can be intuited through the

senses and is contained in the phenomenon.”—This natural and important

question forms the real cause of the necessity of a transcendental

doctrine of the faculty of judgement, with the purpose, to wit, of

showing how pure conceptions of the understanding can be applied to

phenomena. In all other sciences, where the conceptions by which the

object is thought in the general are not so different and heterogeneous

from those which represent the object in concreto—as it is given, it is

quite unnecessary to institute any special inquiries concerning the

application of the former to the latter.

Now it is quite clear that there must be some third thing, which on the

one side is homogeneous with the category, and with the phenomenon on

the other, and so makes the application of the former to the latter

possible. This mediating representation must be pure (without any

empirical content), and yet must on the one side be intellectual, on

the other sensuous. Such a representation is the transcendental schema.

The conception of the understanding contains pure synthetical unity of

the manifold in general. Time, as the formal condition of the manifold

of the internal sense, consequently of the conjunction of all

representations, contains à priori a manifold in the pure intuition.

Now a transcendental determination of time is so far homogeneous with

the category, which constitutes the unity thereof, that it is universal

and rests upon a rule à priori. On the other hand, it is so far

homogeneous with the phenomenon, inasmuch as time is contained in every

empirical representation of the manifold. Thus an application of the

category to phenomena becomes possible, by means of the transcendental

determination of time, which, as the schema of the conceptions of the

understanding, mediates the subsumption of the latter under the former.

After what has been proved in our deduction of the categories, no one,

it is to be hoped, can hesitate as to the proper decision of the

question, whether the employment of these pure conceptions of the

understanding ought to be merely empirical or also transcendental; in

other words, whether the categories, as conditions of a possible

experience, relate à priori solely to phenomena, or whether, as

conditions of the possibility of things in general, their application

can be extended to objects as things in themselves. For we have there

seen that conceptions are quite impossible, and utterly without

signification, unless either to them, or at least to the elements of

which they consist, an object be given; and that, consequently, they

cannot possibly apply to objects as things in themselves without regard

to the question whether and how these may be given to us; and, further,

that the only manner in which objects can be given to us is by means of

the modification of our sensibility; and, finally, that pure à priori

conceptions, in addition to the function of the understanding in the

category, must contain à priori formal conditions of sensibility (of

the internal sense, namely), which again contain the general condition

under which alone the category can be applied to any object. This

formal and pure condition of sensibility, to which the conception of

the understanding is restricted in its employment, we shall name the

schema of the conception of the understanding, and the procedure of the

understanding with these schemata we shall call the schematism of the

pure understanding.

The schema is, in itself, always a mere product of the imagination.

But, as the synthesis of imagination has for its aim no single

intuition, but merely unity in the determination of sensibility, the

schema is clearly distinguishable from the image. Thus, if I place five

points one after another.... this is an image of the number five. On

the other hand, if I only think a number in general, which may be

either five or a hundred, this thought is rather the representation of

a method of representing in an image a sum (e.g., a thousand) in

conformity with a conception, than the image itself, an image which I

should find some little difficulty in reviewing, and comparing with the

conception. Now this representation of a general procedure of the

imagination to present its image to a conception, I call the schema of

this conception.

In truth, it is not images of objects, but schemata, which lie at the

foundation of our pure sensuous conceptions. No image could ever be

adequate to our conception of a triangle in general. For the

generalness of the conception it never could attain to, as this

includes under itself all triangles, whether right-angled,

acute-angled, etc., whilst the image would always be limited to a

single part of this sphere. The schema of the triangle can exist

nowhere else than in thought, and it indicates a rule of the synthesis

of the imagination in regard to pure figures in space. Still less is an

object of experience, or an image of the object, ever to the empirical

conception. On the contrary, the conception always relates immediately

to the schema of the imagination, as a rule for the determination of

our intuition, in conformity with a certain general conception. The

conception of a dog indicates a rule, according to which my imagination

can delineate the figure of a four-footed animal in general, without

being limited to any particular individual form which experience

presents to me, or indeed to any possible image that I can represent to

myself in concreto. This schematism of our understanding in regard to

phenomena and their mere form, is an art, hidden in the depths of the

human soul, whose true modes of action we shall only with difficulty

discover and unveil. Thus much only can we say: “The image is a product

of the empirical faculty of the productive imagination—the schema of

sensuous conceptions (of figures in space, for example) is a product,

and, as it were, a monogram of the pure imagination à priori, whereby

and according to which images first become possible, which, however,

can be connected with the conception only mediately by means of the

schema which they indicate, and are in themselves never fully adequate

to it.” On the other hand, the schema of a pure conception of the

understanding is something that cannot be reduced into any image—it is

nothing else than the pure synthesis expressed by the category,

conformably, to a rule of unity according to conceptions. It is a

transcendental product of the imagination, a product which concerns the

determination of the internal sense, according to conditions of its

form (time) in respect to all representations, in so far as these

representations must be conjoined à priori in one conception,

conformably to the unity of apperception.

Without entering upon a dry and tedious analysis of the essential

requisites of transcendental schemata of the pure conceptions of the

understanding, we shall rather proceed at once to give an explanation

of them according to the order of the categories, and in connection

therewith.

For the external sense the pure image of all quantities (quantorum) is

space; the pure image of all objects of sense in general, is time. But

the pure schema of quantity (quantitatis) as a conception of the

understanding, is number, a representation which comprehends the

successive addition of one to one (homogeneous quantities). Thus,

number is nothing else than the unity of the synthesis of the manifold

in a homogeneous intuition, by means of my generating time itself in my

apprehension of the intuition.

Reality, in the pure conception of the understanding, is that which

corresponds to a sensation in general; that, consequently, the

conception of which indicates a being (in time). Negation is that the

conception of which represents a not-being (in time). The opposition of

these two consists therefore in the difference of one and the same

time, as a time filled or a time empty. Now as time is only the form of

intuition, consequently of objects as phenomena, that which in objects

corresponds to sensation is the transcendental matter of all objects as

things in themselves (Sachheit, reality). Now every sensation has a

degree or quantity by which it can fill time, that is to say, the

internal sense in respect of the representation of an object, more or

less, until it vanishes into nothing (= 0 = negatio). Thus there is a

relation and connection between reality and negation, or rather a

transition from the former to the latter, which makes every reality

representable to us as a quantum; and the schema of a reality as the

quantity of something in so far as it fills time, is exactly this

continuous and uniform generation of the reality in time, as we descend

in time from the sensation which has a certain degree, down to the

vanishing thereof, or gradually ascend from negation to the quantity

thereof.

The schema of substance is the permanence of the real in time; that is,

the representation of it as a substratum of the empirical determination

of time; a substratum which therefore remains, whilst all else changes.

(Time passes not, but in it passes the existence of the changeable. To

time, therefore, which is itself unchangeable and permanent,

corresponds that which in the phenomenon is unchangeable in existence,

that is, substance, and it is only by it that the succession and

coexistence of phenomena can be determined in regard to time.)

The schema of cause and of the causality of a thing is the real which,

when posited, is always followed by something else. It consists,

therefore, in the succession of the manifold, in so far as that

succession is subjected to a rule.

The schema of community (reciprocity of action and reaction), or the

reciprocal causality of substances in respect of their accidents, is

the coexistence of the determinations of the one with those of the

other, according to a general rule.

The schema of possibility is the accordance of the synthesis of

different representations with the conditions of time in general (as,

for example, opposites cannot exist together at the same time in the

same thing, but only after each other), and is therefore the

determination of the representation of a thing at any time.

The schema of reality is existence in a determined time.

The schema of necessity is the existence of an object in all time.

It is clear, from all this, that the schema of the category of quantity

contains and represents the generation (synthesis) of time itself, in

the successive apprehension of an object; the schema of quality the

synthesis of sensation with the representation of time, or the filling

up of time; the schema of relation the relation of perceptions to each

other in all time (that is, according to a rule of the determination of

time): and finally, the schema of modality and its categories, time

itself, as the correlative of the determination of an object—whether it

does belong to time, and how. The schemata, therefore, are nothing but

à priori determinations of time according to rules, and these, in

regard to all possible objects, following the arrangement of the

categories, relate to the series in time, the content in time, the

order in time, and finally, to the complex or totality in time.

Hence it is apparent that the schematism of the understanding, by means

of the transcendental synthesis of the imagination, amounts to nothing

else than the unity of the manifold of intuition in the internal sense,

and thus indirectly to the unity of apperception, as a function

corresponding to the internal sense (a receptivity). Thus, the schemata

of the pure conceptions of the understanding are the true and only

conditions whereby our understanding receives an application to

objects, and consequently significance. Finally, therefore, the

categories are only capable of empirical use, inasmuch as they serve

merely to subject phenomena to the universal rules of synthesis, by

means of an à priori necessary unity (on account of the necessary union

of all consciousness in one original apperception); and so to render

them susceptible of a complete connection in one experience. But within

this whole of possible experience lie all our cognitions, and in the

universal relation to this experience consists transcendental truth,

which antecedes all empirical truth, and renders the latter possible.

It is, however, evident at first sight, that although the schemata of

sensibility are the sole agents in realizing the categories, they do,

nevertheless, also restrict them, that is, they limit the categories by

conditions which lie beyond the sphere of understanding—namely, in

sensibility. Hence the schema is properly only the phenomenon, or the

sensuous conception of an object in harmony with the category. (Numerus

est quantitas phaenomenon—sensatio realitas phaenomenon; constans et

perdurabile rerum substantia phaenomenon—aeternitas, necessitas,

phaenomena, etc.) Now, if we remove a restrictive condition, we thereby

amplify, it appears, the formerly limited conception. In this way, the

categories in their pure signification, free from all conditions of

sensibility, ought to be valid of things as they are, and not, as the

schemata represent them, merely as they appear; and consequently the

categories must have a significance far more extended, and wholly

independent of all schemata. In truth, there does always remain to the

pure conceptions of the understanding, after abstracting every sensuous

condition, a value and significance, which is, however, merely logical.

But in this case, no object is given them, and therefore they have no

meaning sufficient to afford us a conception of an object. The notion

of substance, for example, if we leave out the sensuous determination

of permanence, would mean nothing more than a something which can be

cogitated as subject, without the possibility of becoming a predicate

to anything else. Of this representation I can make nothing, inasmuch

as it does not indicate to me what determinations the thing possesses

which must thus be valid as premier subject. Consequently, the

categories, without schemata are merely functions of the understanding

for the production of conceptions, but do not represent any object.

This significance they derive from sensibility, which at the same time

realizes the understanding and restricts it.

Chapter II. System of all Principles of the Pure Understanding

In the foregoing chapter we have merely considered the general

conditions under which alone the transcendental faculty of judgement is

justified in using the pure conceptions of the understanding for

synthetical judgements. Our duty at present is to exhibit in systematic

connection those judgements which the understanding really produces à

priori. For this purpose, our table of the categories will certainly

afford us the natural and safe guidance. For it is precisely the

categories whose application to possible experience must constitute all

pure à priori cognition of the understanding; and the relation of which

to sensibility will, on that very account, present us with a complete

and systematic catalogue of all the transcendental principles of the

use of the understanding.

Principles à priori are so called, not merely because they contain in

themselves the grounds of other judgements, but also because they

themselves are not grounded in higher and more general cognitions. This

peculiarity, however, does not raise them altogether above the need of

a proof. For although there could be found no higher cognition, and

therefore no objective proof, and although such a principle rather

serves as the foundation for all cognition of the object, this by no

means hinders us from drawing a proof from the subjective sources of

the possibility of the cognition of an object. Such a proof is

necessary, moreover, because without it the principle might be liable

to the imputation of being a mere gratuitous assertion.

In the second place, we shall limit our investigations to those

principles which relate to the categories. For as to the principles of

transcendental æsthetic, according to which space and time are the

conditions of the possibility of things as phenomena, as also the

restriction of these principles, namely, that they cannot be applied to

objects as things in themselves—these, of course, do not fall within

the scope of our present inquiry. In like manner, the principles of

mathematical science form no part of this system, because they are all

drawn from intuition, and not from the pure conception of the

understanding. The possibility of these principles, however, will

necessarily be considered here, inasmuch as they are synthetical

judgements à priori, not indeed for the purpose of proving their

accuracy and apodeictic certainty, which is unnecessary, but merely to

render conceivable and deduce the possibility of such evident à priori

cognitions.

But we shall have also to speak of the principle of analytical

judgements, in opposition to synthetical judgements, which is the

proper subject of our inquiries, because this very opposition will free

the theory of the latter from all ambiguity, and place it clearly

before our eyes in its true nature.

SYSTEM OF THE PRINCIPLES OF THE PURE UNDERSTANDING

Section I. Of the Supreme Principle of all Analytical Judgements

Whatever may be the content of our cognition, and in whatever manner

our cognition may be related to its object, the universal, although

only negative conditions of all our judgements is that they do not

contradict themselves; otherwise these judgements are in themselves

(even without respect to the object) nothing. But although there may

exist no contradiction in our judgement, it may nevertheless connect

conceptions in such a manner that they do not correspond to the object,

or without any grounds either à priori or à posteriori for arriving at

such a judgement, and thus, without being self-contradictory, a

judgement may nevertheless be either false or groundless.

Now, the proposition: “No subject can have a predicate that contradicts

it,” is called the principle of contradiction, and is a universal but

purely negative criterion of all truth. But it belongs to logic alone,

because it is valid of cognitions, merely as cognitions and without

respect to their content, and declares that the contradiction entirely

nullifies them. We can also, however, make a positive use of this

principle, that is, not merely to banish falsehood and error (in so far

as it rests upon contradiction), but also for the cognition of truth.

For if the judgement is analytical, be it affirmative or negative, its

truth must always be recognizable by means of the principle of

contradiction. For the contrary of that which lies and is cogitated as

conception in the cognition of the object will be always properly

negatived, but the conception itself must always be affirmed of the

object, inasmuch as the contrary thereof would be in contradiction to

the object.

We must therefore hold the principle of contradiction to be the

universal and fully sufficient Principle of all analytical cognition.

But as a sufficient criterion of truth, it has no further utility or

authority. For the fact that no cognition can be at variance with this

principle without nullifying itself, constitutes this principle the

sine qua non, but not the determining ground of the truth of our

cognition. As our business at present is properly with the synthetical

part of our knowledge only, we shall always be on our guard not to

transgress this inviolable principle; but at the same time not to

expect from it any direct assistance in the establishment of the truth

of any synthetical proposition.

There exists, however, a formula of this celebrated principle—a

principle merely formal and entirely without content—which contains a

synthesis that has been inadvertently and quite unnecessarily mixed up

with it. It is this: “It is impossible for a thing to be and not to be

at the same time.” Not to mention the superfluousness of the addition

of the word impossible to indicate the apodeictic certainty, which

ought to be self-evident from the proposition itself, the proposition

is affected by the condition of time, and as it were says: “A thing =

A, which is something = B, cannot at the same time be non-B.” But both,

B as well as non-B, may quite well exist in succession. For example, a

man who is young cannot at the same time be old; but the same man can

very well be at one time young, and at another not young, that is, old.

Now the principle of contradiction as a merely logical proposition must

not by any means limit its application merely to relations of time, and

consequently a formula like the preceding is quite foreign to its true

purpose. The misunderstanding arises in this way. We first of all

separate a predicate of a thing from the conception of the thing, and

afterwards connect with this predicate its opposite, and hence do not

establish any contradiction with the subject, but only with its

predicate, which has been conjoined with the subject synthetically—a

contradiction, moreover, which obtains only when the first and second

predicate are affirmed in the same time. If I say: “A man who is

ignorant is not learned,” the condition “at the same time” must be

added, for he who is at one time ignorant, may at another be learned.

But if I say: “No ignorant man is a learned man,” the proposition is

analytical, because the characteristic ignorance is now a constituent

part of the conception of the subject; and in this case the negative

proposition is evident immediately from the proposition of

contradiction, without the necessity of adding the condition “the same

time.” This is the reason why I have altered the formula of this

principle—an alteration which shows very clearly the nature of an

analytical proposition.

Section II. Of the Supreme Principle of all Synthetical Judgements

The explanation of the possibility of synthetical judgements is a task

with which general logic has nothing to do; indeed she needs not even

be acquainted with its name. But in transcendental logic it is the most

important matter to be dealt with—indeed the only one, if the question

is of the possibility of synthetical judgements à priori, the

conditions and extent of their validity. For when this question is

fully decided, it can reach its aim with perfect ease, the

determination, to wit, of the extent and limits of the pure

understanding.

In an analytical judgement I do not go beyond the given conception, in

order to arrive at some decision respecting it. If the judgement is

affirmative, I predicate of the conception only that which was already

cogitated in it; if negative, I merely exclude from the conception its

contrary. But in synthetical judgements, I must go beyond the given

conception, in order to cogitate, in relation with it, something quite

different from that which was cogitated in it, a relation which is

consequently never one either of identity or contradiction, and by

means of which the truth or error of the judgement cannot be discerned

merely from the judgement itself.

Granted, then, that we must go out beyond a given conception, in order

to compare it synthetically with another, a third thing is necessary,

in which alone the synthesis of two conceptions can originate. Now what

is this tertium quid that is to be the medium of all synthetical

judgements? It is only a complex in which all our representations are

contained, the internal sense to wit, and its form à priori, time.

The synthesis of our representations rests upon the imagination; their

synthetical unity (which is requisite to a judgement), upon the unity

of apperception. In this, therefore, is to be sought the possibility of

synthetical judgements, and as all three contain the sources of à

priori representations, the possibility of pure synthetical judgements

also; nay, they are necessary upon these grounds, if we are to possess

a knowledge of objects, which rests solely upon the synthesis of

representations.

If a cognition is to have objective reality, that is, to relate to an

object, and possess sense and meaning in respect to it, it is necessary

that the object be given in some way or another. Without this, our

conceptions are empty, and we may indeed have thought by means of them,

but by such thinking we have not, in fact, cognized anything, we have

merely played with representation. To give an object, if this

expression be understood in the sense of “to present” the object, not

mediately but immediately in intuition, means nothing else than to

apply the representation of it to experience, be that experience real

or only possible. Space and time themselves, pure as these conceptions

are from all that is empirical, and certain as it is that they are

represented fully à priori in the mind, would be completely without

objective validity, and without sense and significance, if their

necessary use in the objects of experience were not shown. Nay, the

representation of them is a mere schema, that always relates to the

reproductive imagination, which calls up the objects of experience,

without which they have no meaning. And so it is with all conceptions

without distinction.

The possibility of experience is, then, that which gives objective

reality to all our à priori cognitions. Now experience depends upon the

synthetical unity of phenomena, that is, upon a synthesis according to

conceptions of the object of phenomena in general, a synthesis without

which experience never could become knowledge, but would be merely a

rhapsody of perceptions, never fitting together into any connected

text, according to rules of a thoroughly united (possible)

consciousness, and therefore never subjected to the transcendental and

necessary unity of apperception. Experience has therefore for a

foundation, à priori principles of its form, that is to say, general

rules of unity in the synthesis of phenomena, the objective reality of

which rules, as necessary conditions even of the possibility of

experience can which rules, as necessary conditions—even of the

possibility of experience—can always be shown in experience. But apart

from this relation, à priori synthetical propositions are absolutely

impossible, because they have no third term, that is, no pure object,

in which the synthetical unity can exhibit the objective reality of its

conceptions.

Although, then, respecting space, or the forms which productive

imagination describes therein, we do cognize much à priori in

synthetical judgements, and are really in no need of experience for

this purpose, such knowledge would nevertheless amount to nothing but a

busy trifling with a mere chimera, were not space to be considered as

the condition of the phenomena which constitute the material of

external experience. Hence those pure synthetical judgements do relate,

though but mediately, to possible experience, or rather to the

possibility of experience, and upon that alone is founded the objective

validity of their synthesis.

While then, on the one hand, experience, as empirical synthesis, is the

only possible mode of cognition which gives reality to all other

synthesis; on the other hand, this latter synthesis, as cognition à

priori, possesses truth, that is, accordance with its object, only in

so far as it contains nothing more than what is necessary to the

synthetical unity of experience.

Accordingly, the supreme principle of all synthetical judgements is:

“Every object is subject to the necessary conditions of the synthetical

unity of the manifold of intuition in a possible experience.”

À priori synthetical judgements are possible when we apply the formal

conditions of the à priori intuition, the synthesis of the imagination,

and the necessary unity of that synthesis in a transcendental

apperception, to a possible cognition of experience, and say: “The

conditions of the possibility of experience in general are at the same

time conditions of the possibility of the objects of experience, and

have, for that reason, objective validity in an à priori synthetical

judgement.”

Section III. Systematic Representation of all Synthetical Principles of

the Pure Understanding

That principles exist at all is to be ascribed solely to the pure

understanding, which is not only the faculty of rules in regard to that

which happens, but is even the source of principles according to which

everything that can be presented to us as an object is necessarily

subject to rules, because without such rules we never could attain to

cognition of an object. Even the laws of nature, if they are

contemplated as principles of the empirical use of the understanding,

possess also a characteristic of necessity, and we may therefore at

least expect them to be determined upon grounds which are valid à

priori and antecedent to all experience. But all laws of nature,

without distinction, are subject to higher principles of the

understanding, inasmuch as the former are merely applications of the

latter to particular cases of experience. These higher principles alone

therefore give the conception, which contains the necessary condition,

and, as it were, the exponent of a rule; experience, on the other hand,

gives the case which comes under the rule.

There is no danger of our mistaking merely empirical principles for

principles of the pure understanding, or conversely; for the character

of necessity, according to conceptions which distinguish the latter,

and the absence of this in every empirical proposition, how extensively

valid soever it may be, is a perfect safeguard against confounding

them. There are, however, pure principles à priori, which nevertheless

I should not ascribe to the pure understanding—for this reason, that

they are not derived from pure conceptions, but (although by the

mediation of the understanding) from pure intuitions. But understanding

is the faculty of conceptions. Such principles mathematical science

possesses, but their application to experience, consequently their

objective validity, nay the possibility of such à priori synthetical

cognitions (the deduction thereof) rests entirely upon the pure

understanding.

On this account, I shall not reckon among my principles those of

mathematics; though I shall include those upon the possibility and

objective validity à priori, of principles of the mathematical science,

which, consequently, are to be looked upon as the principle of these,

and which proceed from conceptions to intuition, and not from intuition

to conceptions.

In the application of the pure conceptions of the understanding to

possible experience, the employment of their synthesis is either

mathematical or dynamical, for it is directed partly on the intuition

alone, partly on the existence of a phenomenon. But the à priori

conditions of intuition are in relation to a possible experience

absolutely necessary, those of the existence of objects of a possible

empirical intuition are in themselves contingent. Hence the principles

of the mathematical use of the categories will possess a character of

absolute necessity, that is, will be apodeictic; those, on the other

hand, of the dynamical use, the character of an à priori necessity

indeed, but only under the condition of empirical thought in an

experience, therefore only mediately and indirectly. Consequently they

will not possess that immediate evidence which is peculiar to the

former, although their application to experience does not, for that

reason, lose its truth and certitude. But of this point we shall be

better able to judge at the conclusion of this system of principles.

The table of the categories is naturally our guide to the table of

principles, because these are nothing else than rules for the objective

employment of the former. Accordingly, all principles of the pure

understanding are:

1

Axioms

of Intuition

2 3

Anticipations Analogies

of Perception of Experience

4

Postulates of

Empirical Thought

in general

These appellations I have chosen advisedly, in order that we might not

lose sight of the distinctions in respect of the evidence and the

employment of these principles. It will, however, soon appear that—a

fact which concerns both the evidence of these principles, and the à

priori determination of phenomena—according to the categories of

quantity and quality (if we attend merely to the form of these), the

principles of these categories are distinguishable from those of the

two others, in as much as the former are possessed of an intuitive, but

the latter of a merely discursive, though in both instances a complete,

certitude. I shall therefore call the former mathematical, and the

latter dynamical principles.[27] It must be observed, however, that by

these terms I mean just as little in the one case the principles of

mathematics as those of general (physical) dynamics in the other. I

have here in view merely the principles of the pure understanding, in

their application to the internal sense (without distinction of the

representations given therein), by means of which the sciences of

mathematics and dynamics become possible. Accordingly, I have named

these principles rather with reference to their application than their

content; and I shall now proceed to consider them in the order in which

they stand in the table.

[27] All combination (conjunctio) is either composition (compositio)

or connection (nexus). The former is the synthesis of a manifold, the

parts of which do not necessarily belong to each other. For example,

the two triangles into which a square is divided by a diagonal, do not

necessarily belong to each other, and of this kind is the synthesis of

the homogeneous in everything that can be mathematically considered.

This synthesis can be divided into those of aggregation and coalition,

the former of which is applied to extensive, the latter to intensive

quantities. The second sort of combination (nexus) is the synthesis of

a manifold, in so far as its parts do belong necessarily to each

other; for example, the accident to a substance, or the effect to the

cause. Consequently it is a synthesis of that which though

heterogeneous, is represented as connected à priori. This

combination—not an arbitrary one—I entitle dynamical because it

concerns the connection of the existence of the manifold. This, again,

may be divided into the physical synthesis, of the phenomena divided

among each other, and the metaphysical synthesis, or the connection of

phenomena à priori in the faculty of cognition.

1. AXIOMS OF INTUITION.

The principle of these is: All Intuitions are Extensive Quantities.

PROOF.

All phenomena contain, as regards their form, an intuition in space and

time, which lies à priori at the foundation of all without exception.

Phenomena, therefore, cannot be apprehended, that is, received into

empirical consciousness otherwise than through the synthesis of a

manifold, through which the representations of a determinate space or

time are generated; that is to say, through the composition of the

homogeneous and the consciousness of the synthetical unity of this

manifold (homogeneous). Now the consciousness of a homogeneous manifold

in intuition, in so far as thereby the representation of an object is

rendered possible, is the conception of a quantity (quanti).

Consequently, even the perception of an object as phenomenon is

possible only through the same synthetical unity of the manifold of the

given sensuous intuition, through which the unity of the composition of

the homogeneous manifold in the conception of a quantity is cogitated;

that is to say, all phenomena are quantities, and extensive quantities,

because as intuitions in space or time they must be represented by

means of the same synthesis through which space and time themselves are

determined.

An extensive quantity I call that wherein the representation of the

parts renders possible (and therefore necessarily antecedes) the

representation of the whole. I cannot represent to myself any line,

however small, without drawing it in thought, that is, without

generating from a point all its parts one after another, and in this

way alone producing this intuition. Precisely the same is the case with

every, even the smallest, portion of time. I cogitate therein only the

successive progress from one moment to another, and hence, by means of

the different portions of time and the addition of them, a determinate

quantity of time is produced. As the pure intuition in all phenomena is

either time or space, so is every phenomenon in its character of

intuition an extensive quantity, inasmuch as it can only be cognized in

our apprehension by successive synthesis (from part to part). All

phenomena are, accordingly, to be considered as aggregates, that is, as

a collection of previously given parts; which is not the case with

every sort of quantities, but only with those which are represented and

apprehended by us as extensive.

On this successive synthesis of the productive imagination, in the

generation of figures, is founded the mathematics of extension, or

geometry, with its axioms, which express the conditions of sensuous

intuition à priori, under which alone the schema of a pure conception

of external intuition can exist; for example, “be tween two points only

one straight line is possible,” “two straight lines cannot enclose a

space,” etc. These are the axioms which properly relate only to

quantities (quanta) as such.

But, as regards the quantity of a thing (quantitas), that is to say,

the answer to the question: “How large is this or that object?”

although, in respect to this question, we have various propositions

synthetical and immediately certain (indemonstrabilia); we have, in the

proper sense of the term, no axioms. For example, the propositions: “If

equals be added to equals, the wholes are equal”; “If equals be taken

from equals, the remainders are equal”; are analytical, because I am

immediately conscious of the identity of the production of the one

quantity with the production of the other; whereas axioms must be à

priori synthetical propositions. On the other hand, the self-evident

propositions as to the relation of numbers, are certainly synthetical

but not universal, like those of geometry, and for this reason cannot

be called axioms, but numerical formulae. That 7 + 5 = 12 is not an

analytical proposition. For neither in the representation of seven, nor

of five, nor of the composition of the two numbers, do I cogitate the

number twelve. (Whether I cogitate the number in the addition of both,

is not at present the question; for in the case of an analytical

proposition, the only point is whether I really cogitate the predicate

in the representation of the subject.) But although the proposition is

synthetical, it is nevertheless only a singular proposition. In so far

as regard is here had merely to the synthesis of the homogeneous (the

units), it cannot take place except in one manner, although our use of

these numbers is afterwards general. If I say: “A triangle can be

constructed with three lines, any two of which taken together are

greater than the third,” I exercise merely the pure function of the

productive imagination, which may draw the lines longer or shorter and

construct the angles at its pleasure. On the contrary, the number seven

is possible only in one manner, and so is likewise the number twelve,

which results from the synthesis of seven and five. Such propositions,

then, cannot be termed axioms (for in that case we should have an

infinity of these), but numerical formulae.

This transcendental principle of the mathematics of phenomena greatly

enlarges our à priori cognition. For it is by this principle alone that

pure mathematics is rendered applicable in all its precision to objects

of experience, and without it the validity of this application would

not be so self-evident; on the contrary, contradictions and confusions

have often arisen on this very point. Phenomena are not things in

themselves. Empirical intuition is possible only through pure intuition

(of space and time); consequently, what geometry affirms of the latter,

is indisputably valid of the former. All evasions, such as the

statement that objects of sense do not conform to the rules of

construction in space (for example, to the rule of the infinite

divisibility of lines or angles), must fall to the ground. For, if

these objections hold good, we deny to space, and with it to all

mathematics, objective validity, and no longer know wherefore, and how

far, mathematics can be applied to phenomena. The synthesis of spaces

and times as the essential form of all intuition, is that which renders

possible the apprehension of a phenomenon, and therefore every external

experience, consequently all cognition of the objects of experience;

and whatever mathematics in its pure use proves of the former, must

necessarily hold good of the latter. All objections are but the

chicaneries of an ill-instructed reason, which erroneously thinks to

liberate the objects of sense from the formal conditions of our

sensibility, and represents these, although mere phenomena, as things

in themselves, presented as such to our understanding. But in this

case, no à priori synthetical cognition of them could be possible,

consequently not through pure conceptions of space and the science

which determines these conceptions, that is to say, geometry, would

itself be impossible.

2. ANTICIPATIONS OF PERCEPTION.

The principle of these is: In all phenomena the Real, that which is an

object of sensation, has Intensive Quantity, that is, has a Degree.

PROOF.

Perception is empirical consciousness, that is to say, a consciousness

which contains an element of sensation. Phenomena as objects of

perception are not pure, that is, merely formal intuitions, like space

and time, for they cannot be perceived in themselves.[28] They contain,

then, over and above the intuition, the materials for an object

(through which is represented something existing in space or time),

that is to say, they contain the real of sensation, as a representation

merely subjective, which gives us merely the consciousness that the

subject is affected, and which we refer to some external object. Now, a

gradual transition from empirical consciousness to pure consciousness

is possible, inasmuch as the real in this consciousness entirely

vanishes, and there remains a merely formal consciousness (à priori) of

the manifold in time and space; consequently there is possible a

synthesis also of the production of the quantity of a sensation from

its commencement, that is, from the pure intuition = 0 onwards up to a

certain quantity of the sensation. Now as sensation in itself is not an

objective representation, and in it is to be found neither the

intuition of space nor of time, it cannot possess any extensive

quantity, and yet there does belong to it a quantity (and that by means

of its apprehension, in which empirical consciousness can within a

certain time rise from nothing = 0 up to its given amount),

consequently an intensive quantity. And thus we must ascribe intensive

quantity, that is, a degree of influence on sense to all objects of

perception, in so far as this perception contains sensation.

[28] They can be perceived only as phenomena, and some part of them

must always belong to the non-ego; whereas pure intuitions are

entirely the products of the mind itself, and as such are cognized _in

themselves.—Tr_

All cognition, by means of which I am enabled to cognize and determine

à priori what belongs to empirical cognition, may be called an

anticipation; and without doubt this is the sense in which Epicurus

employed his expression prholepsis. But as there is in phenomena

something which is never cognized à priori, which on this account

constitutes the proper difference between pure and empirical cognition,

that is to say, sensation (as the matter of perception), it follows,

that sensation is just that element in cognition which cannot be at all

anticipated. On the other hand, we might very well term the pure

determinations in space and time, as well in regard to figure as to

quantity, anticipations of phenomena, because they represent à priori

that which may always be given à posteriori in experience. But suppose

that in every sensation, as sensation in general, without any

particular sensation being thought of, there existed something which

could be cognized à priori, this would deserve to be called

anticipation in a special sense—special, because it may seem surprising

to forestall experience, in that which concerns the matter of

experience, and which we can only derive from itself. Yet such really

is the case here.

Apprehension[29], by means of sensation alone, fills only one moment,

that is, if I do not take into consideration a succession of many

sensations. As that in the phenomenon, the apprehension of which is not

a successive synthesis advancing from parts to an entire

representation, sensation has therefore no extensive quantity; the want

of sensation in a moment of time would represent it as empty,

consequently = 0. That which in the empirical intuition corresponds to

sensation is reality (realitas phaenomenon); that which corresponds to

the absence of it, negation = 0. Now every sensation is capable of a

diminution, so that it can decrease, and thus gradually disappear.

Therefore, between reality in a phenomenon and negation, there exists a

continuous concatenation of many possible intermediate sensations, the

difference of which from each other is always smaller than that between

the given sensation and zero, or complete negation. That is to say, the

real in a phenomenon has always a quantity, which however is not

discoverable in apprehension, inasmuch as apprehension take place by

means of mere sensation in one instant, and not by the successive

synthesis of many sensations, and therefore does not progress from

parts to the whole. Consequently, it has a quantity, but not an

extensive quantity.

[29] Apprehension is the Kantian word for preception, in the largest

sense in which we employ that term. It is the genus which includes

under i, as species, perception proper and sensation proper—Tr

Now that quantity which is apprehended only as unity, and in which

plurality can be represented only by approximation to negation = 0, I

term intensive quantity. Consequently, reality in a phenomenon has

intensive quantity, that is, a degree. If we consider this reality as

cause (be it of sensation or of another reality in the phenomenon, for

example, a change), we call the degree of reality in its character of

cause a momentum, for example, the momentum of weight; and for this

reason, that the degree only indicates that quantity the apprehension

of which is not successive, but instantaneous. This, however, I touch

upon only in passing, for with causality I have at present nothing to

do.

Accordingly, every sensation, consequently every reality in phenomena,

however small it may be, has a degree, that is, an intensive quantity,

which may always be lessened, and between reality and negation there

exists a continuous connection of possible realities, and possible

smaller perceptions. Every colour—for example, red—has a degree, which,

be it ever so small, is never the smallest, and so is it always with

heat, the momentum of weight, etc.

This property of quantities, according to which no part of them is the

smallest possible (no part simple), is called their continuity. Space

and time are quanta continua, because no part of them can be given,

without enclosing it within boundaries (points and moments),

consequently, this given part is itself a space or a time. Space,

therefore, consists only of spaces, and time of times. Points and

moments are only boundaries, that is, the mere places or positions of

their limitation. But places always presuppose intuitions which are to

limit or determine them; and we cannot conceive either space or time

composed of constituent parts which are given before space or time.

Such quantities may also be called flowing, because synthesis (of the

productive imagination) in the production of these quantities is a

progression in time, the continuity of which we are accustomed to

indicate by the expression flowing.

All phenomena, then, are continuous quantities, in respect both to

intuition and mere perception (sensation, and with it reality). In the

former case they are extensive quantities; in the latter, intensive.

When the synthesis of the manifold of a phenomenon is interrupted,

there results merely an aggregate of several phenomena, and not

properly a phenomenon as a quantity, which is not produced by the mere

continuation of the productive synthesis of a certain kind, but by the

repetition of a synthesis always ceasing. For example, if I call

thirteen dollars a sum or quantity of money, I employ the term quite

correctly, inasmuch as I understand by thirteen dollars the value of a

mark in standard silver, which is, to be sure, a continuous quantity,

in which no part is the smallest, but every part might constitute a

piece of money, which would contain material for still smaller pieces.

If, however, by the words thirteen dollars I understand so many coins

(be their value in silver what it may), it would be quite erroneous to

use the expression a quantity of dollars; on the contrary, I must call

them aggregate, that is, a number of coins. And as in every number we

must have unity as the foundation, so a phenomenon taken as unity is a

quantity, and as such always a continuous quantity (quantum continuum).

Now, seeing all phenomena, whether considered as extensive or

intensive, are continuous quantities, the proposition: “All change

(transition of a thing from one state into another) is continuous,”

might be proved here easily, and with mathematical evidence, were it

not that the causality of a change lies, entirely beyond the bounds of

a transcendental philosophy, and presupposes empirical principles. For

of the possibility of a cause which changes the condition of things,

that is, which determines them to the contrary to a certain given

state, the understanding gives us à priori no knowledge; not merely

because it has no insight into the possibility of it (for such insight

is absent in several à priori cognitions), but because the notion of

change concerns only certain determinations of phenomena, which

experience alone can acquaint us with, while their cause lies in the

unchangeable. But seeing that we have nothing which we could here

employ but the pure fundamental conceptions of all possible experience,

among which of course nothing empirical can be admitted, we dare not,

without injuring the unity of our system, anticipate general physical

science, which is built upon certain fundamental experiences.

Nevertheless, we are in no want of proofs of the great influence which

the principle above developed exercises in the anticipation of

perceptions, and even in supplying the want of them, so far as to

shield us against the false conclusions which otherwise we might rashly

draw.

If all reality in perception has a degree, between which and negation

there is an endless sequence of ever smaller degrees, and if,

nevertheless, every sense must have a determinate degree of receptivity

for sensations; no perception, and consequently no experience is

possible, which can prove, either immediately or mediately, an entire

absence of all reality in a phenomenon; in other words, it is

impossible ever to draw from experience a proof of the existence of

empty space or of empty time. For in the first place, an entire absence

of reality in a sensuous intuition cannot of course be an object of

perception; secondly, such absence cannot be deduced from the

contemplation of any single phenomenon, and the difference of the

degrees in its reality; nor ought it ever to be admitted in explanation

of any phenomenon. For if even the complete intuition of a determinate

space or time is thoroughly real, that is, if no part thereof is empty,

yet because every reality has its degree, which, with the extensive

quantity of the phenomenon unchanged, can diminish through endless

gradations down to nothing (the void), there must be infinitely

graduated degrees, with which space or time is filled, and the

intensive quantity in different phenomena may be smaller or greater,

although the extensive quantity of the intuition remains equal and

unaltered.

We shall give an example of this. Almost all natural philosophers,

remarking a great difference in the quantity of the matter of different

kinds in bodies with the same volume (partly on account of the momentum

of gravity or weight, partly on account of the momentum of resistance

to other bodies in motion), conclude unanimously that this volume

(extensive quantity of the phenomenon) must be void in all bodies,

although in different proportion. But who would suspect that these for

the most part mathematical and mechanical inquirers into nature should

ground this conclusion solely on a metaphysical hypothesis—a sort of

hypothesis which they profess to disparage and avoid? Yet this they do,

in assuming that the real in space (I must not here call it

impenetrability or weight, because these are empirical conceptions) is

always identical, and can only be distinguished according to its

extensive quantity, that is, multiplicity. Now to this presupposition,

for which they can have no ground in experience, and which consequently

is merely metaphysical, I oppose a transcendental demonstration, which

it is true will not explain the difference in the filling up of spaces,

but which nevertheless completely does away with the supposed necessity

of the above-mentioned presupposition that we cannot explain the said

difference otherwise than by the hypothesis of empty spaces. This

demonstration, moreover, has the merit of setting the understanding at

liberty to conceive this distinction in a different manner, if the

explanation of the fact requires any such hypothesis. For we perceive

that although two equal spaces may be completely filled by matters

altogether different, so that in neither of them is there left a single

point wherein matter is not present, nevertheless, every reality has

its degree (of resistance or of weight), which, without diminution of

the extensive quantity, can become less and less ad infinitum, before

it passes into nothingness and disappears. Thus an expansion which

fills a space—for example, caloric, or any other reality in the

phenomenal world—can decrease in its degrees to infinity, yet without

leaving the smallest part of the space empty; on the contrary, filling

it with those lesser degrees as completely as another phenomenon could

with greater. My intention here is by no means to maintain that this is

really the case with the difference of matters, in regard to their

specific gravity; I wish only to prove, from a principle of the pure

understanding, that the nature of our perceptions makes such a mode of

explanation possible, and that it is erroneous to regard the real in a

phenomenon as equal quoad its degree, and different only quoad its

aggregation and extensive quantity, and this, too, on the pretended

authority of an à priori principle of the understanding.

Nevertheless, this principle of the anticipation of perception must

somewhat startle an inquirer whom initiation into transcendental

philosophy has rendered cautious. We must naturally entertain some

doubt whether or not the understanding can enounce any such synthetical

proposition as that respecting the degree of all reality in phenomena,

and consequently the possibility of the internal difference of

sensation itself—abstraction being made of its empirical quality. Thus

it is a question not unworthy of solution: “How the understanding can

pronounce synthetically and à priori respecting phenomena, and thus

anticipate these, even in that which is peculiarly and merely

empirical, that, namely, which concerns sensation itself?”

The quality of sensation is in all cases merely empirical, and cannot

be represented à priori (for example, colours, taste, etc.). But the

real—that which corresponds to sensation—in opposition to negation = 0,

only represents something the conception of which in itself contains a

being (ein seyn), and signifies nothing but the synthesis in an

empirical consciousness. That is to say, the empirical consciousness in

the internal sense can be raised from 0 to every higher degree, so that

the very same extensive quantity of intuition, an illuminated surface,

for example, excites as great a sensation as an aggregate of many other

surfaces less illuminated. We can therefore make complete abstraction

of the extensive quantity of a phenomenon, and represent to ourselves

in the mere sensation in a certain momentum, a synthesis of homogeneous

ascension from 0 up to the given empirical consciousness, All

sensations therefore as such are given only à posteriori, but this

property thereof, namely, that they have a degree, can be known à

priori. It is worthy of remark, that in respect to quantities in

general, we can cognize à priori only a single quality, namely,

continuity; but in respect to all quality (the real in phenomena), we

cannot cognize à priori anything more than the intensive quantity

thereof, namely, that they have a degree. All else is left to

experience.

3. ANALOGIES OF EXPERIENCE.

The principle of these is: Experience is possible only through the

representation of a necessary connection of Perceptions.

PROOF.

Experience is an empirical cognition; that is to say, a cognition which

determines an object by means of perceptions. It is therefore a

synthesis of perceptions, a synthesis which is not itself contained in

perception, but which contains the synthetical unity of the manifold of

perception in a consciousness; and this unity constitutes the essential

of our cognition of objects of the senses, that is, of experience (not

merely of intuition or sensation). Now in experience our perceptions

come together contingently, so that no character of necessity in their

connection appears, or can appear from the perceptions themselves,

because apprehension is only a placing together of the manifold of

empirical intuition, and no representation of a necessity in the

connected existence of the phenomena which apprehension brings

together, is to be discovered therein. But as experience is a cognition

of objects by means of perceptions, it follows that the relation of the

existence of the existence of the manifold must be represented in

experience not as it is put together in time, but as it is objectively

in time. And as time itself cannot be perceived, the determination of

the existence of objects in time can only take place by means of their

connection in time in general, consequently only by means of à priori

connecting conceptions. Now as these conceptions always possess the

character of necessity, experience is possible only by means of a

representation of the necessary connection of perception.

The three modi of time are permanence, succession, and coexistence.

Accordingly, there are three rules of all relations of time in

phenomena, according to which the existence of every phenomenon is

determined in respect of the unity of all time, and these antecede all

experience and render it possible.

The general principle of all three analogies rests on the necessary

unity of apperception in relation to all possible empirical

consciousness (perception) at every time, consequently, as this unity

lies à priori at the foundation of all mental operations, the principle

rests on the synthetical unity of all phenomena according to their

relation in time. For the original apperception relates to our internal

sense (the complex of all representations), and indeed relates à priori

to its form, that is to say, the relation of the manifold empirical

consciousness in time. Now this manifold must be combined in original

apperception according to relations of time—a necessity imposed by the

à priori transcendental unity of apperception, to which is subjected

all that can belong to my (i.e., my own) cognition, and therefore all

that can become an object for me. This synthetical and à priori

determined unity in relation of perceptions in time is therefore the

rule: “All empirical determinations of time must be subject to rules of

the general determination of time”; and the analogies of experience, of

which we are now about to treat, must be rules of this nature.

These principles have this peculiarity, that they do not concern

phenomena, and the synthesis of the empirical intuition thereof, but

merely the existence of phenomena and their relation to each other in

regard to this existence. Now the mode in which we apprehend a thing in

a phenomenon can be determined à priori in such a manner that the rule

of its synthesis can give, that is to say, can produce this à priori

intuition in every empirical example. But the existence of phenomena

cannot be known à priori, and although we could arrive by this path at

a conclusion of the fact of some existence, we could not cognize that

existence determinately, that is to say, we should be incapable of

anticipating in what respect the empirical intuition of it would be

distinguishable from that of others.

The two principles above mentioned, which I called mathematical, in

consideration of the fact of their authorizing the application of

mathematic phenomena, relate to these phenomena only in regard to their

possibility, and instruct us how phenomena, as far as regards their

intuition or the real in their perception, can be generated according

to the rules of a mathematical synthesis. Consequently, numerical

quantities, and with them the determination of a phenomenon as a

quantity, can be employed in the one case as well as in the other.

Thus, for example, out of 200,000 illuminations by the moon, I might

compose and give à priori, that is construct, the degree of our

sensations of the sun-light.[30] We may therefore entitle these two

principles constitutive.

[30] Kant’s meaning is: The two principles enunciated under the heads

of “Axioms of Intuition,” and “Anticipations of Perception,” authorize

the application to phenomena of determinations of size and number,

that is of mathematic. For example, I may compute the light of the

sun, and say that its quantity is a certain number of times greater

than that of the moon. In the same way, heat is measured by the

comparison of its different effects on water, &c., and on mercury in a

thermometer.—Tr

The case is very different with those principles whose province it is

to subject the existence of phenomena to rules à priori. For as

existence does not admit of being constructed, it is clear that they

must only concern the relations of existence and be merely regulative

principles. In this case, therefore, neither axioms nor anticipations

are to be thought of. Thus, if a perception is given us, in a certain

relation of time to other (although undetermined) perceptions, we

cannot then say à priori, what and how great (in quantity) the other

perception necessarily connected with the former is, but only how it is

connected, quoad its existence, in this given modus of time. Analogies

in philosophy mean something very different from that which they

represent in mathematics. In the latter they are formulae, which

enounce the equality of two relations of quantity, and are always

constitutive, so that if two terms of the proportion are given, the

third is also given, that is, can be constructed by the aid of these

formulae. But in philosophy, analogy is not the equality of two

quantitative but of two qualitative relations. In this case, from three

given terms, I can give à priori and cognize the relation to a fourth

member, but not this fourth term itself, although I certainly possess a

rule to guide me in the search for this fourth term in experience, and

a mark to assist me in discovering it. An analogy of experience is

therefore only a rule according to which unity of experience must arise

out of perceptions in respect to objects (phenomena) not as a

constitutive, but merely as a regulative principle. The same holds good

also of the postulates of empirical thought in general, which relate to

the synthesis of mere intuition (which concerns the form of phenomena),

the synthesis of perception (which concerns the matter of phenomena),

and the synthesis of experience (which concerns the relation of these

perceptions). For they are only regulative principles, and clearly

distinguishable from the mathematical, which are constitutive, not

indeed in regard to the certainty which both possess à priori, but in

the mode of evidence thereof, consequently also in the manner of

demonstration.

But what has been observed of all synthetical propositions, and must be

particularly remarked in this place, is this, that these analogies

possess significance and validity, not as principles of the

transcendental, but only as principles of the empirical use of the

understanding, and their truth can therefore be proved only as such,

and that consequently the phenomena must not be subjoined directly

under the categories, but only under their schemata. For if the objects

to which those principles must be applied were things in themselves, it

would be quite impossible to cognize aught concerning them

synthetically à priori. But they are nothing but phenomena; a complete

knowledge of which—a knowledge to which all principles à priori must at

last relate—is the only possible experience. It follows that these

principles can have nothing else for their aim than the conditions of

the empirical cognition in the unity of synthesis of phenomena. But

this synthesis is cogitated only in the schema of the pure conception

of the understanding, of whose unity, as that of a synthesis in

general, the category contains the function unrestricted by any

sensuous condition. These principles will therefore authorize us to

connect phenomena according to an analogy, with the logical and

universal unity of conceptions, and consequently to employ the

categories in the principles themselves; but in the application of them

to experience, we shall use only their schemata, as the key to their

proper application, instead of the categories, or rather the latter as

restricting conditions, under the title of “formulae” of the former.

A. FIRST ANALOGY.

Principle of the Permanence of Substance.

In all changes of phenomena, substance is permanent, and the quantum

thereof in nature is neither increased nor diminished.

PROOF.

All phenomena exist in time, wherein alone as substratum, that is, as

the permanent form of the internal intuition, coexistence and

succession can be represented. Consequently time, in which all changes

of phenomena must be cogitated, remains and changes not, because it is

that in which succession and coexistence can be represented only as

determinations thereof. Now, time in itself cannot be an object of

perception. It follows that in objects of perception, that is, in

phenomena, there must be found a substratum which represents time in

general, and in which all change or coexistence can be perceived by

means of the relation of phenomena to it. But the substratum of all

reality, that is, of all that pertains to the existence of things, is

substance; all that pertains to existence can be cogitated only as a

determination of substance. Consequently, the permanent, in relation to

which alone can all relations of time in phenomena be determined, is

substance in the world of phenomena, that is, the real in phenomena,

that which, as the substratum of all change, remains ever the same.

Accordingly, as this cannot change in existence, its quantity in nature

can neither be increased nor diminished.

Our apprehension of the manifold in a phenomenon is always successive,

is Consequently always changing. By it alone we could, therefore, never

determine whether this manifold, as an object of experience, is

coexistent or successive, unless it had for a foundation something

fixed and permanent, of the existence of which all succession and

coexistence are nothing but so many modes (modi of time). Only in the

permanent, then, are relations of time possible (for simultaneity and

succession are the only relations in time); that is to say, the

permanent is the substratum of our empirical representation of time

itself, in which alone all determination of time is possible.

Permanence is, in fact, just another expression for time, as the

abiding correlate of all existence of phenomena, and of all change, and

of all coexistence. For change does not affect time itself, but only

the phenomena in time (just as coexistence cannot be regarded as a

modus of time itself, seeing that in time no parts are coexistent, but

all successive). If we were to attribute succession to time itself, we

should be obliged to cogitate another time, in which this succession

would be possible. It is only by means of the permanent that existence

in different parts of the successive series of time receives a

quantity, which we entitle duration. For in mere succession, existence

is perpetually vanishing and recommencing, and therefore never has even

the least quantity. Without the permanent, then, no relation in time is

possible. Now, time in itself is not an object of perception;

consequently the permanent in phenomena must be regarded as the

substratum of all determination of time, and consequently also as the

condition of the possibility of all synthetical unity of perceptions,

that is, of experience; and all existence and all change in time can

only be regarded as a mode in the existence of that which abides

unchangeably. Therefore, in all phenomena, the permanent is the object

in itself, that is, the substance (phenomenon); but all that changes or

can change belongs only to the mode of the existence of this substance

or substances, consequently to its determinations.

I find that in all ages not only the philosopher, but even the common

understanding, has preposited this permanence as a substratum of all

change in phenomena; indeed, I am compelled to believe that they will

always accept this as an indubitable fact. Only the philosopher

expresses himself in a more precise and definite manner, when he says:

“In all changes in the world, the substance remains, and the accidents

alone are changeable.” But of this decidedly synthetical proposition, I

nowhere meet with even an attempt at proof; nay, it very rarely has the

good fortune to stand, as it deserves to do, at the head of the pure

and entirely à priori laws of nature. In truth, the statement that

substance is permanent, is tautological. For this very permanence is

the ground on which we apply the category of substance to the

phenomenon; and we should have been obliged to prove that in all

phenomena there is something permanent, of the existence of which the

changeable is nothing but a determination. But because a proof of this

nature cannot be dogmatical, that is, cannot be drawn from conceptions,

inasmuch as it concerns a synthetical proposition à priori, and as

philosophers never reflected that such propositions are valid only in

relation to possible experience, and therefore cannot be proved except

by means of a deduction of the possibility of experience, it is no

wonder that while it has served as the foundation of all experience

(for we feel the need of it in empirical cognition), it has never been

supported by proof.

A philosopher was asked: “What is the weight of smoke?” He answered:

“Subtract from the weight of the burnt wood the weight of the remaining

ashes, and you will have the weight of the smoke.” Thus he presumed it

to be incontrovertible that even in fire the matter (substance) does

not perish, but that only the form of it undergoes a change. In like

manner was the saying: “From nothing comes nothing,” only another

inference from the principle or permanence, or rather of the

ever-abiding existence of the true subject in phenomena. For if that in

the phenomenon which we call substance is to be the proper substratum

of all determination of time, it follows that all existence in past as

well as in future time, must be determinable by means of it alone.

Hence we are entitled to apply the term substance to a phenomenon, only

because we suppose its existence in all time, a notion which the word

permanence does not fully express, as it seems rather to be referable

to future time. However, the internal necessity perpetually to be, is

inseparably connected with the necessity always to have been, and so

the expression may stand as it is. “Gigni de nihilo nihil; in nihilum

nil posse reverti,”[31] are two propositions which the ancients never

parted, and which people nowadays sometimes mistakenly disjoin, because

they imagine that the propositions apply to objects as things in

themselves, and that the former might be inimical to the dependence

(even in respect of its substance also) of the world upon a supreme

cause. But this apprehension is entirely needless, for the question in

this case is only of phenomena in the sphere of experience, the unity

of which never could be possible, if we admitted the possibility that

new things (in respect of their substance) should arise. For in that

case, we should lose altogether that which alone can represent the

unity of time, to wit, the identity of the substratum, as that through

which alone all change possesses complete and thorough unity. This

permanence is, however, nothing but the manner in which we represent to

ourselves the existence of things in the phenomenal world.

[31] Persius, Satirae, iii.83-84.

The determinations of a substance, which are only particular modes of

its existence, are called accidents. They are always real, because they

concern the existence of substance (negations are only determinations,

which express the non-existence of something in the substance). Now, if

to this real in the substance we ascribe a particular existence (for

example, to motion as an accident of matter), this existence is called

inherence, in contradistinction to the existence of substance, which we

call subsistence. But hence arise many misconceptions, and it would be

a more accurate and just mode of expression to designate the accident

only as the mode in which the existence of a substance is positively

determined. Meanwhile, by reason of the conditions of the logical

exercise of our understanding, it is impossible to avoid separating, as

it were, that which in the existence of a substance is subject to

change, whilst the substance remains, and regarding it in relation to

that which is properly permanent and radical. On this account, this

category of substance stands under the title of relation, rather

because it is the condition thereof than because it contains in itself

any relation.

Now, upon this notion of permanence rests the proper notion of the

conception change. Origin and extinction are not changes of that which

originates or becomes extinct. Change is but a mode of existence, which

follows on another mode of existence of the same object; hence all that

changes is permanent, and only the condition thereof changes. Now since

this mutation affects only determinations, which can have a beginning

or an end, we may say, employing an expression which seems somewhat

paradoxical: “Only the permanent (substance) is subject to change; the

mutable suffers no change, but rather alternation, that is, when

certain determinations cease, others begin.”

Change, when, cannot be perceived by us except in substances, and

origin or extinction in an absolute sense, that does not concern merely

a determination of the permanent, cannot be a possible perception, for

it is this very notion of the permanent which renders possible the

representation of a transition from one state into another, and from

non-being to being, which, consequently, can be empirically cognized

only as alternating determinations of that which is permanent. Grant

that a thing absolutely begins to be; we must then have a point of time

in which it was not. But how and by what can we fix and determine this

point of time, unless by that which already exists? For a void

time—preceding—is not an object of perception; but if we connect this

beginning with objects which existed previously, and which continue to

exist till the object in question in question begins to be, then the

latter can only be a determination of the former as the permanent. The

same holds good of the notion of extinction, for this presupposes the

empirical representation of a time, in which a phenomenon no longer

exists.

Substances (in the world of phenomena) are the substratum of all

determinations of time. The beginning of some, and the ceasing to be of

other substances, would utterly do away with the only condition of the

empirical unity of time; and in that case phenomena would relate to two

different times, in which, side by side, existence would pass; which is

absurd. For there is only one time in which all different times must be

placed, not as coexistent, but as successive.

Accordingly, permanence is a necessary condition under which alone

phenomena, as things or objects, are determinable in a possible

experience. But as regards the empirical criterion of this necessary

permanence, and with it of the substantiality of phenomena, we shall

find sufficient opportunity to speak in the sequel.

B. SECOND ANALOGY.

Principle of the Succession of Time According to the Law of Causality.

All changes take place according to the law of the connection of Cause

and Effect.

PROOF.

(That all phenomena in the succession of time are only changes, that

is, a successive being and non-being of the determinations of

substance, which is permanent; consequently that a being of substance

itself which follows on the non-being thereof, or a non-being of

substance which follows on the being thereof, in other words, that the

origin or extinction of substance itself, is impossible—all this has

been fully established in treating of the foregoing principle. This

principle might have been expressed as follows: “All alteration

(succession) of phenomena is merely change”; for the changes of

substance are not origin or extinction, because the conception of

change presupposes the same subject as existing with two opposite

determinations, and consequently as permanent. After this premonition,

we shall proceed to the proof.)

I perceive that phenomena succeed one another, that is to say, a state

of things exists at one time, the opposite of which existed in a former

state. In this case, then, I really connect together two perceptions in

time. Now connection is not an operation of mere sense and intuition,

but is the product of a synthetical faculty of imagination, which

determines the internal sense in respect of a relation of time. But

imagination can connect these two states in two ways, so that either

the one or the other may antecede in time; for time in itself cannot be

an object of perception, and what in an object precedes and what

follows cannot be empirically determined in relation to it. I am only

conscious, then, that my imagination places one state before and the

other after; not that the one state antecedes the other in the object.

In other words, the objective relation of the successive phenomena

remains quite undetermined by means of mere perception. Now in order

that this relation may be cognized as determined, the relation between

the two states must be so cogitated that it is thereby determined as

necessary, which of them must be placed before and which after, and not

conversely. But the conception which carries with it a necessity of

synthetical unity, can be none other than a pure conception of the

understanding which does not lie in mere perception; and in this case

it is the conception of “the relation of cause and effect,” the former

of which determines the latter in time, as its necessary consequence,

and not as something which might possibly antecede (or which might in

some cases not be perceived to follow). It follows that it is only

because we subject the sequence of phenomena, and consequently all

change, to the law of causality, that experience itself, that is,

empirical cognition of phenomena, becomes possible; and consequently,

that phenomena themselves, as objects of experience, are possible only

by virtue of this law.

Our apprehension of the manifold of phenomena is always successive. The

representations of parts succeed one another. Whether they succeed one

another in the object also, is a second point for reflection, which was

not contained in the former. Now we may certainly give the name of

object to everything, even to every representation, so far as we are

conscious thereof; but what this word may mean in the case of

phenomena, not merely in so far as they (as representations) are

objects, but only in so far as they indicate an object, is a question

requiring deeper consideration. In so far as they, regarded merely as

representations, are at the same time objects of consciousness, they

are not to be distinguished from apprehension, that is, reception into

the synthesis of imagination, and we must therefore say: “The manifold

of phenomena is always produced successively in the mind.” If phenomena

were things in themselves, no man would be able to conjecture from the

succession of our representations how this manifold is connected in the

object; for we have to do only with our representations. How things may

be in themselves, without regard to the representations through which

they affect us, is utterly beyond the sphere of our cognition. Now

although phenomena are not things in themselves, and are nevertheless

the only thing given to us to be cognized, it is my duty to show what

sort of connection in time belongs to the manifold in phenomena

themselves, while the representation of this manifold in apprehension

is always successive. For example, the apprehension of the manifold in

the phenomenon of a house which stands before me, is successive. Now

comes the question whether the manifold of this house is in itself

successive—which no one will be at all willing to grant. But, so soon

as I raise my conception of an object to the transcendental

signification thereof, I find that the house is not a thing in itself,

but only a phenomenon, that is, a representation, the transcendental

object of which remains utterly unknown. What then am I to understand

by the question: “How can the manifold be connected in the phenomenon

itself—not considered as a thing in itself, but merely as a

phenomenon?” Here that which lies in my successive apprehension is

regarded as representation, whilst the phenomenon which is given me,

notwithstanding that it is nothing more than a complex of these

representations, is regarded as the object thereof, with which my

conception, drawn from the representations of apprehension, must

harmonize. It is very soon seen that, as accordance of the cognition

with its object constitutes truth, the question now before us can only

relate to the formal conditions of empirical truth; and that the

phenomenon, in opposition to the representations of apprehension, can

only be distinguished therefrom as the object of them, if it is subject

to a rule which distinguishes it from every other apprehension, and

which renders necessary a mode of connection of the manifold. That in

the phenomenon which contains the condition of this necessary rule of

apprehension, is the object.

Let us now proceed to our task. That something happens, that is to say,

that something or some state exists which before was not, cannot be

empirically perceived, unless a phenomenon precedes, which does not

contain in itself this state. For a reality which should follow upon a

void time, in other words, a beginning, which no state of things

precedes, can just as little be apprehended as the void time itself.

Every apprehension of an event is therefore a perception which follows

upon another perception. But as this is the case with all synthesis of

apprehension, as I have shown above in the example of a house, my

apprehension of an event is not yet sufficiently distinguished from

other apprehensions. But I remark also that if in a phenomenon which

contains an occurrence, I call the antecedent state of my perception,

A, and the following state, B, the perception B can only follow A in

apprehension, and the perception A cannot follow B, but only precede

it. For example, I see a ship float down the stream of a river. My

perception of its place lower down follows upon my perception of its

place higher up the course of the river, and it is impossible that, in

the apprehension of this phenomenon, the vessel should be perceived

first below and afterwards higher up the stream. Here, therefore, the

order in the sequence of perceptions in apprehension is determined; and

by this order apprehension is regulated. In the former example, my

perceptions in the apprehension of a house might begin at the roof and

end at the foundation, or vice versa; or I might apprehend the manifold

in this empirical intuition, by going from left to right, and from

right to left. Accordingly, in the series of these perceptions, there

was no determined order, which necessitated my beginning at a certain

point, in order empirically to connect the manifold. But this rule is

always to be met with in the perception of that which happens, and it

makes the order of the successive perceptions in the apprehension of

such a phenomenon necessary.

I must, therefore, in the present case, deduce the subjective sequence

of apprehension from the objective sequence of phenomena, for otherwise

the former is quite undetermined, and one phenomenon is not

distinguishable from another. The former alone proves nothing as to the

connection of the manifold in an object, for it is quite arbitrary. The

latter must consist in the order of the manifold in a phenomenon,

according to which order the apprehension of one thing (that which

happens) follows that of another thing (which precedes), in conformity

with a rule. In this way alone can I be authorized to say of the

phenomenon itself, and not merely of my own apprehension, that a

certain order or sequence is to be found therein. That is, in other

words, I cannot arrange my apprehension otherwise than in this order.

In conformity with this rule, then, it is necessary that in that which

antecedes an event there be found the condition of a rule, according to

which in this event follows always and necessarily; but I cannot

reverse this and go back from the event, and determine (by

apprehension) that which antecedes it. For no phenomenon goes back from

the succeeding point of time to the preceding point, although it does

certainly relate to a preceding point of time; from a given time, on

the other hand, there is always a necessary progression to the

determined succeeding time. Therefore, because there certainly is

something that follows, I must of necessity connect it with something

else, which antecedes, and upon which it follows, in conformity with a

rule, that is necessarily, so that the event, as conditioned, affords

certain indication of a condition, and this condition determines the

event.

Let us suppose that nothing precedes an event, upon which this event

must follow in conformity with a rule. All sequence of perception would

then exist only in apprehension, that is to say, would be merely

subjective, and it could not thereby be objectively determined what

thing ought to precede, and what ought to follow in perception. In such

a case, we should have nothing but a play of representations, which

would possess no application to any object. That is to say, it would

not be possible through perception to distinguish one phenomenon from

another, as regards relations of time; because the succession in the

act of apprehension would always be of the same sort, and therefore

there would be nothing in the phenomenon to determine the succession,

and to render a certain sequence objectively necessary. And, in this

case, I cannot say that two states in a phenomenon follow one upon the

other, but only that one apprehension follows upon another. But this is

merely subjective, and does not determine an object, and consequently

cannot be held to be cognition of an object—not even in the phenomenal

world.

Accordingly, when we know in experience that something happens, we

always presuppose that something precedes, whereupon it follows in

conformity with a rule. For otherwise I could not say of the object

that it follows; because the mere succession in my apprehension, if it

be not determined by a rule in relation to something preceding, does

not authorize succession in the object. Only, therefore, in reference

to a rule, according to which phenomena are determined in their

sequence, that is, as they happen, by the preceding state, can I make

my subjective synthesis (of apprehension) objective, and it is only

under this presupposition that even the experience of an event is

possible.

No doubt it appears as if this were in thorough contradiction to all

the notions which people have hitherto entertained in regard to the

procedure of the human understanding. According to these opinions, it

is by means of the perception and comparison of similar consequences

following upon certain antecedent phenomena that the understanding is

led to the discovery of a rule, according to which certain events

always follow certain phenomena, and it is only by this process that we

attain to the conception of cause. Upon such a basis, it is clear that

this conception must be merely empirical, and the rule which it

furnishes us with—“Everything that happens must have a cause”—would be

just as contingent as experience itself. The universality and necessity

of the rule or law would be perfectly spurious attributes of it.

Indeed, it could not possess universal validity, inasmuch as it would

not in this case be à priori, but founded on deduction. But the same is

the case with this law as with other pure à priori representations

(e.g., space and time), which we can draw in perfect clearness and

completeness from experience, only because we had already placed them

therein, and by that means, and by that alone, had rendered experience

possible. Indeed, the logical clearness of this representation of a

rule, determining the series of events, is possible only when we have

made use thereof in experience. Nevertheless, the recognition of this

rule, as a condition of the synthetical unity of phenomena in time, was

the ground of experience itself and consequently preceded it à priori.

It is now our duty to show by an example that we never, even in

experience, attribute to an object the notion of succession or effect

(of an event—that is, the happening of something that did not exist

before), and distinguish it from the subjective succession of

apprehension, unless when a rule lies at the foundation, which compels

us to observe this order of perception in preference to any other, and

that, indeed, it is this necessity which first renders possible the

representation of a succession in the object.

We have representations within us, of which also we can be conscious.

But, however widely extended, however accurate and thoroughgoing this

consciousness may be, these representations are still nothing more than

representations, that is, internal determinations of the mind in this

or that relation of time. Now how happens it that to these

representations we should set an object, or that, in addition to their

subjective reality, as modifications, we should still further attribute

to them a certain unknown objective reality? It is clear that objective

significancy cannot consist in a relation to another representation (of

that which we desire to term object), for in that case the question

again arises: “How does this other representation go out of itself, and

obtain objective significancy over and above the subjective, which is

proper to it, as a determination of a state of mind?” If we try to

discover what sort of new property the relation to an object gives to

our subjective representations, and what new importance they thereby

receive, we shall find that this relation has no other effect than that

of rendering necessary the connection of our representations in a

certain manner, and of subjecting them to a rule; and that conversely,

it is only because a certain order is necessary in the relations of

time of our representations, that objective significancy is ascribed to

them.

In the synthesis of phenomena, the manifold of our representations is

always successive. Now hereby is not represented an object, for by

means of this succession, which is common to all apprehension, no one

thing is distinguished from another. But so soon as I perceive or

assume that in this succession there is a relation to a state

antecedent, from which the representation follows in accordance with a

rule, so soon do I represent something as an event, or as a thing that

happens; in other words, I cognize an object to which I must assign a

certain determinate position in time, which cannot be altered, because

of the preceding state in the object. When, therefore, I perceive that

something happens, there is contained in this representation, in the

first place, the fact, that something antecedes; because, it is only in

relation to this that the phenomenon obtains its proper relation of

time, in other words, exists after an antecedent time, in which it did

not exist. But it can receive its determined place in time only by the

presupposition that something existed in the foregoing state, upon

which it follows inevitably and always, that is, in conformity with a

rule. From all this it is evident that, in the first place, I cannot

reverse the order of succession, and make that which happens precede

that upon which it follows; and that, in the second place, if the

antecedent state be posited, a certain determinate event inevitably and

necessarily follows. Hence it follows that there exists a certain order

in our representations, whereby the present gives a sure indication of

some previously existing state, as a correlate, though still

undetermined, of the existing event which is given—a correlate which

itself relates to the event as its consequence, conditions it, and

connects it necessarily with itself in the series of time.

If then it be admitted as a necessary law of sensibility, and

consequently a formal condition of all perception, that the preceding

necessarily determines the succeeding time (inasmuch as I cannot arrive

at the succeeding except through the preceding), it must likewise be an

indispensable law of empirical representation of the series of time

that the phenomena of the past determine all phenomena in the

succeeding time, and that the latter, as events, cannot take place,

except in so far as the former determine their existence in time, that

is to say, establish it according to a rule. For it is of course only

in phenomena that we can empirically cognize this continuity in the

connection of times.

For all experience and for the possibility of experience, understanding

is indispensable, and the first step which it takes in this sphere is

not to render the representation of objects clear, but to render the

representation of an object in general, possible. It does this by

applying the order of time to phenomena, and their existence. In other

words, it assigns to each phenomenon, as a consequence, a place in

relation to preceding phenomena, determined à priori in time, without

which it could not harmonize with time itself, which determines a place

à priori to all its parts. This determination of place cannot be

derived from the relation of phenomena to absolute time (for it is not

an object of perception); but, on the contrary, phenomena must

reciprocally determine the places in time of one another, and render

these necessary in the order of time. In other words, whatever follows

or happens, must follow in conformity with a universal rule upon that

which was contained in the foregoing state. Hence arises a series of

phenomena, which, by means of the understanding, produces and renders

necessary exactly the same order and continuous connection in the

series of our possible perceptions, as is found à priori in the form of

internal intuition (time), in which all our perceptions must have

place.

That something happens, then, is a perception which belongs to a

possible experience, which becomes real only because I look upon the

phenomenon as determined in regard to its place in time, consequently

as an object, which can always be found by means of a rule in the

connected series of my perceptions. But this rule of the determination

of a thing according to succession in time is as follows: “In what

precedes may be found the condition, under which an event always (that

is, necessarily) follows.” From all this it is obvious that the

principle of cause and effect is the principle of possible experience,

that is, of objective cognition of phenomena, in regard to their

relations in the succession of time.

The proof of this fundamental proposition rests entirely on the

following momenta of argument. To all empirical cognition belongs the

synthesis of the manifold by the imagination, a synthesis which is

always successive, that is, in which the representations therein always

follow one another. But the order of succession in imagination is not

determined, and the series of successive representations may be taken

retrogressively as well as progressively. But if this synthesis is a

synthesis of apprehension (of the manifold of a given phenomenon), then

the order is determined in the object, or to speak more accurately,

there is therein an order of successive synthesis which determines an

object, and according to which something necessarily precedes, and when

this is posited, something else necessarily follows. If, then, my

perception is to contain the cognition of an event, that is, of

something which really happens, it must be an empirical judgement,

wherein we think that the succession is determined; that is, it

presupposes another phenomenon, upon which this event follows

necessarily, or in conformity with a rule. If, on the contrary, when I

posited the antecedent, the event did not necessarily follow, I should

be obliged to consider it merely as a subjective play of my

imagination, and if in this I represented to myself anything as

objective, I must look upon it as a mere dream. Thus, the relation of

phenomena (as possible perceptions), according to which that which

happens is, as to its existence, necessarily determined in time by

something which antecedes, in conformity with a rule—in other words,

the relation of cause and effect—is the condition of the objective

validity of our empirical judgements in regard to the sequence of

perceptions, consequently of their empirical truth, and therefore of

experience. The principle of the relation of causality in the

succession of phenomena is therefore valid for all objects of

experience, because it is itself the ground of the possibility of

experience.

Here, however, a difficulty arises, which must be resolved. The

principle of the connection of causality among phenomena is limited in

our formula to the succession thereof, although in practice we find

that the principle applies also when the phenomena exist together in

the same time, and that cause and effect may be simultaneous. For

example, there is heat in a room, which does not exist in the open air.

I look about for the cause, and find it to be the fire, Now the fire as

the cause is simultaneous with its effect, the heat of the room. In

this case, then, there is no succession as regards time, between cause

and effect, but they are simultaneous; and still the law holds good.

The greater part of operating causes in nature are simultaneous with

their effects, and the succession in time of the latter is produced

only because the cause cannot achieve the total of its effect in one

moment. But at the moment when the effect first arises, it is always

simultaneous with the causality of its cause, because, if the cause had

but a moment before ceased to be, the effect could not have arisen.

Here it must be specially remembered that we must consider the order of

time and not the lapse thereof. The relation remains, even though no

time has elapsed. The time between the causality of the cause and its

immediate effect may entirely vanish, and the cause and effect be thus

simultaneous, but the relation of the one to the other remains always

determinable according to time. If, for example, I consider a leaden

ball, which lies upon a cushion and makes a hollow in it, as a cause,

then it is simultaneous with the effect. But I distinguish the two

through the relation of time of the dynamical connection of both. For

if I lay the ball upon the cushion, then the hollow follows upon the

before smooth surface; but supposing the cushion has, from some cause

or another, a hollow, there does not thereupon follow a leaden ball.

Thus, the law of succession of time is in all instances the only

empirical criterion of effect in relation to the causality of the

antecedent cause. The glass is the cause of the rising of the water

above its horizontal surface, although the two phenomena are

contemporaneous. For, as soon as I draw some water with the glass from

a larger vessel, an effect follows thereupon, namely, the change of the

horizontal state which the water had in the large vessel into a

concave, which it assumes in the glass.

This conception of causality leads us to the conception of action; that

of action, to the conception of force; and through it, to the

conception of substance. As I do not wish this critical essay, the sole

purpose of which is to treat of the sources of our synthetical

cognition à priori, to be crowded with analyses which merely explain,

but do not enlarge the sphere of our conceptions, I reserve the

detailed explanation of the above conceptions for a future system of

pure reason. Such an analysis, indeed, executed with great

particularity, may already be found in well-known works on this

subject. But I cannot at present refrain from making a few remarks on

the empirical criterion of a substance, in so far as it seems to be

more evident and more easily recognized through the conception of

action than through that of the permanence of a phenomenon.

Where action (consequently activity and force) exists, substance also

must exist, and in it alone must be sought the seat of that fruitful

source of phenomena. Very well. But if we are called upon to explain

what we mean by substance, and wish to avoid the vice of reasoning in a

circle, the answer is by no means so easy. How shall we conclude

immediately from the action to the permanence of that which acts, this

being nevertheless an essential and peculiar criterion of substance

(phenomenon)? But after what has been said above, the solution of this

question becomes easy enough, although by the common mode of

procedure—merely analysing our conceptions—it would be quite

impossible. The conception of action indicates the relation of the

subject of causality to the effect. Now because all effect consists in

that which happens, therefore in the changeable, the last subject

thereof is the permanent, as the substratum of all that changes, that

is, substance. For according to the principle of causality, actions are

always the first ground of all change in phenomena and, consequently,

cannot be a property of a subject which itself changes, because if this

were the case, other actions and another subject would be necessary to

determine this change. From all this it results that action alone, as

an empirical criterion, is a sufficient proof of the presence of

substantiality, without any necessity on my part of endeavouring to

discover the permanence of substance by a comparison. Besides, by this

mode of induction we could not attain to the completeness which the

magnitude and strict universality of the conception requires. For that

the primary subject of the causality of all arising and passing away,

all origin and extinction, cannot itself (in the sphere of phenomena)

arise and pass away, is a sound and safe conclusion, a conclusion which

leads us to the conception of empirical necessity and permanence in

existence, and consequently to the conception of a substance as

phenomenon.

When something happens, the mere fact of the occurrence, without regard

to that which occurs, is an object requiring investigation. The

transition from the non-being of a state into the existence of it,

supposing that this state contains no quality which previously existed

in the phenomenon, is a fact of itself demanding inquiry. Such an

event, as has been shown in No. A, does not concern substance (for

substance does not thus originate), but its condition or state. It is

therefore only change, and not origin from nothing. If this origin be

regarded as the effect of a foreign cause, it is termed creation, which

cannot be admitted as an event among phenomena, because the very

possibility of it would annihilate the unity of experience. If,

however, I regard all things not as phenomena, but as things in

themselves and objects of understanding alone, they, although

substances, may be considered as dependent, in respect of their

existence, on a foreign cause. But this would require a very different

meaning in the words, a meaning which could not apply to phenomena as

objects of possible experience.

How a thing can be changed, how it is possible that upon one state

existing in one point of time, an opposite state should follow in

another point of time—of this we have not the smallest conception à

priori. There is requisite for this the knowledge of real powers, which

can only be given empirically; for example, knowledge of moving forces,

or, in other words, of certain successive phenomena (as movements)

which indicate the presence of such forces. But the form of every

change, the condition under which alone it can take place as the coming

into existence of another state (be the content of the change, that is,

the state which is changed, what it may), and consequently the

succession of the states themselves can very well be considered à

priori, in relation to the law of causality and the conditions of

time.[32]

[32] It must be remarked that I do not speak of the change of certain

relations, but of the change of the state. Thus, when a body moves in

a uniform manner, it does not change its state (of motion); but only

when all motion increases or decreases.

When a substance passes from one state, a, into another state, b, the

point of time in which the latter exists is different from, and

subsequent to that in which the former existed. In like manner, the

second state, as reality (in the phenomenon), differs from the first,

in which the reality of the second did not exist, as b from zero. That

is to say, if the state, b, differs from the state, a, only in respect

to quantity, the change is a coming into existence of b -a, which in

the former state did not exist, and in relation to which that state is

= O.

Now the question arises how a thing passes from one state = a, into

another state = b. Between two moments there is always a certain time,

and between two states existing in these moments there is always a

difference having a certain quantity (for all parts of phenomena are

in their turn quantities). Consequently, every transition from one

state into another, is always effected in a time contained between

two moments, of which the first determines the state which the thing

leaves, and the second determines the state into which the thing

passes. Both moments, then, are limitations of the time of a change,

consequently of the intermediate state between both, and as such they

belong to the total of the change. Now every change has a cause, which

evidences its causality in the whole time during which the charge takes

place. The cause, therefore, does not produce the change all at once or

in one moment, but in a time, so that, as the time gradually increases

from the commencing instant, a, to its completion at b, in like manner

also, the quantity of the reality (b - a) is generated through the

lesser degrees which are contained between the first and last. All

change is therefore possible only through a continuous action of the

causality, which, in so far as it is uniform, we call a momentum. The

change does not consist of these momenta, but is generated or produced

by them as their effect.

Such is the law of the continuity of all change, the ground of which is

that neither time itself nor any phenomenon in time consists of parts

which are the smallest possible, but that, notwithstanding, the state

of a thing passes in the process of a change through all these parts,

as elements, to its second state. There is no smallest degree of

reality in a phenomenon, just as there is no smallest degree in the

quantity of time; and so the new state of reality grows up out of the

former state, through all the infinite degrees thereof, the differences

of which one from another, taken all together, are less than the

difference between 0 and a.

It is not our business to inquire here into the utility of this

principle in the investigation of nature. But how such a proposition,

which appears so greatly to extend our knowledge of nature, is possible

completely à priori, is indeed a question which deserves investigation,

although the first view seems to demonstrate the truth and reality of

the principle, and the question, how it is possible, may be considered

superfluous. For there are so many groundless pretensions to the

enlargement of our knowledge by pure reason that we must take it as a

general rule to be mistrustful of all such, and without a thoroughgoing

and radical deduction, to believe nothing of the sort even on the

clearest dogmatical evidence.

Every addition to our empirical knowledge, and every advance made in

the exercise of our perception, is nothing more than an extension of

the determination of the internal sense, that is to say, a progression

in time, be objects themselves what they may, phenomena, or pure

intuitions. This progression in time determines everything, and is

itself determined by nothing else. That is to say, the parts of the

progression exist only in time, and by means of the synthesis thereof,

and are not given antecedently to it. For this reason, every transition

in perception to anything which follows upon another in time, is a

determination of time by means of the production of this perception.

And as this determination of time is, always and in all its parts, a

quantity, the perception produced is to be considered as a quantity

which proceeds through all its degrees—no one of which is the smallest

possible—from zero up to its determined degree. From this we perceive

the possibility of cognizing à priori a law of changes—a law, however,

which concerns their form merely. We merely anticipate our own

apprehension, the formal condition of which, inasmuch as it is itself

to be found in the mind antecedently to all given phenomena, must

certainly be capable of being cognized à priori.

Thus, as time contains the sensuous condition à priori of the

possibility of a continuous progression of that which exists to that

which follows it, the understanding, by virtue of the unity of

apperception, contains the condition à priori of the possibility of a

continuous determination of the position in time of all phenomena, and

this by means of the series of causes and effects, the former of which

necessitate the sequence of the latter, and thereby render universally

and for all time, and by consequence, objectively, valid the empirical

cognition of the relations of time.

C. THIRD ANALOGY.

Principle of Coexistence, According to the Law of Reciprocity or

Community.

All substances, in so far as they can be perceived in space at the same

time, exist in a state of complete reciprocity of action.

PROOF.

Things are coexistent, when in empirical intuition the perception of

the one can follow upon the perception of the other, and vice

versa—which cannot occur in the succession of phenomena, as we have

shown in the explanation of the second principle. Thus I can perceive

the moon and then the earth, or conversely, first the earth and then

the moon; and for the reason that my perceptions of these objects can

reciprocally follow each other, I say, they exist contemporaneously.

Now coexistence is the existence of the manifold in the same time. But

time itself is not an object of perception; and therefore we cannot

conclude from the fact that things are placed in the same time, the

other fact, that the perception of these things can follow each other

reciprocally. The synthesis of the imagination in apprehension would

only present to us each of these perceptions as present in the subject

when the other is not present, and contrariwise; but would not show

that the objects are coexistent, that is to say, that, if the one

exists, the other also exists in the same time, and that this is

necessarily so, in order that the perceptions may be capable of

following each other reciprocally. It follows that a conception of the

understanding or category of the reciprocal sequence of the

determinations of phenomena (existing, as they do, apart from each

other, and yet contemporaneously), is requisite to justify us in saying

that the reciprocal succession of perceptions has its foundation in the

object, and to enable us to represent coexistence as objective. But

that relation of substances in which the one contains determinations

the ground of which is in the other substance, is the relation of

influence. And, when this influence is reciprocal, it is the relation

of community or reciprocity. Consequently the coexistence of substances

in space cannot be cognized in experience otherwise than under the

precondition of their reciprocal action. This is therefore the

condition of the possibility of things themselves as objects of

experience.

Things are coexistent, in so far as they exist in one and the same

time. But how can we know that they exist in one and the same time?

Only by observing that the order in the synthesis of apprehension of

the manifold is arbitrary and a matter of indifference, that is to say,

that it can proceed from A, through B, C, D, to E, or contrariwise from

E to A. For if they were successive in time (and in the order, let us

suppose, which begins with A), it is quite impossible for the

apprehension in perception to begin with E and go backwards to A,

inasmuch as A belongs to past time and, therefore, cannot be an object

of apprehension.

Let us assume that in a number of substances considered as phenomena

each is completely isolated, that is, that no one acts upon another.

Then I say that the coexistence of these cannot be an object of

possible perception and that the existence of one cannot, by any mode

of empirical synthesis, lead us to the existence of another. For we

imagine them in this case to be separated by a completely void space,

and thus perception, which proceeds from the one to the other in time,

would indeed determine their existence by means of a following

perception, but would be quite unable to distinguish whether the one

phenomenon follows objectively upon the first, or is coexistent with

it.

Besides the mere fact of existence, then, there must be something by

means of which A determines the position of B in time and, conversely,

B the position of A; because only under this condition can substances

be empirically represented as existing contemporaneously. Now that

alone determines the position of another thing in time which is the

cause of it or of its determinations. Consequently every substance

(inasmuch as it can have succession predicated of it only in respect of

its determinations) must contain the causality of certain

determinations in another substance, and at the same time the effects

of the causality of the other in itself. That is to say, substances

must stand (mediately or immediately) in dynamical community with each

other, if coexistence is to be cognized in any possible experience.

But, in regard to objects of experience, that is absolutely necessary

without which the experience of these objects would itself be

impossible. Consequently it is absolutely necessary that all substances

in the world of phenomena, in so far as they are coexistent, stand in a

relation of complete community of reciprocal action to each other.

The word community has in our language[33] two meanings, and contains

the two notions conveyed in the Latin communio and commercium. We

employ it in this place in the latter sense—that of a dynamical

community, without which even the community of place (communio spatii)

could not be empirically cognized. In our experiences it is easy to

observe that it is only the continuous influences in all parts of space

that can conduct our senses from one object to another; that the light

which plays between our eyes and the heavenly bodies produces a

mediating community between them and us, and thereby evidences their

coexistence with us; that we cannot empirically change our position

(perceive this change), unless the existence of matter throughout the

whole of space rendered possible the perception of the positions we

occupy; and that this perception can prove the contemporaneous

existence of these places only through their reciprocal influence, and

thereby also the coexistence of even the most remote objects—although

in this case the proof is only mediate. Without community, every

perception (of a phenomenon in space) is separated from every other and

isolated, and the chain of empirical representations, that is, of

experience, must, with the appearance of a new object, begin entirely

de novo, without the least connection with preceding representations,

and without standing towards these even in the relation of time. My

intention here is by no means to combat the notion of empty space; for

it may exist where our perceptions cannot exist, inasmuch as they

cannot reach thereto, and where, therefore, no empirical perception of

coexistence takes place. But in this case it is not an object of

possible experience.

[33] German

The following remarks may be useful in the way of explanation. In the

mind, all phenomena, as contents of a possible experience, must exist

in community (communio) of apperception or consciousness, and in so far

as it is requisite that objects be represented as coexistent and

connected, in so far must they reciprocally determine the position in

time of each other and thereby constitute a whole. If this subjective

community is to rest upon an objective basis, or to be applied to

substances as phenomena, the perception of one substance must render

possible the perception of another, and conversely. For otherwise

succession, which is always found in perceptions as apprehensions,

would be predicated of external objects, and their representation of

their coexistence be thus impossible. But this is a reciprocal

influence, that is to say, a real community (commercium) of substances,

without which therefore the empirical relation of coexistence would be

a notion beyond the reach of our minds. By virtue of this commercium,

phenomena, in so far as they are apart from, and nevertheless in

connection with each other, constitute a compositum reale. Such

composita are possible in many different ways. The three dynamical

relations then, from which all others spring, are those of inherence,

consequence, and composition.

These, then, are the three analogies of experience. They are nothing

more than principles of the determination of the existence of phenomena

in time, according to the three modi of this determination; to wit, the

relation to time itself as a quantity (the quantity of existence, that

is, duration), the relation in time as a series or succession, finally,

the relation in time as the complex of all existence (simultaneity).

This unity of determination in regard to time is thoroughly dynamical;

that is to say, time is not considered as that in which experience

determines immediately to every existence its position; for this is

impossible, inasmuch as absolute time is not an object of perception,

by means of which phenomena can be connected with each other. On the

contrary, the rule of the understanding, through which alone the

existence of phenomena can receive synthetical unity as regards

relations of time, determines for every phenomenon its position in

time, and consequently à priori, and with validity for all and every

time.

By nature, in the empirical sense of the word, we understand the

totality of phenomena connected, in respect of their existence,

according to necessary rules, that is, laws. There are therefore

certain laws (which are moreover à priori) which make nature possible;

and all empirical laws can exist only by means of experience, and by

virtue of those primitive laws through which experience itself becomes

possible. The purpose of the analogies is therefore to represent to us

the unity of nature in the connection of all phenomena under certain

exponents, the only business of which is to express the relation of

time (in so far as it contains all existence in itself) to the unity of

apperception, which can exist in synthesis only according to rules. The

combined expression of all is this: “All phenomena exist in one nature,

and must so exist, inasmuch as without this à priori unity, no unity of

experience, and consequently no determination of objects in experience,

is possible.”

As regards the mode of proof which we have employed in treating of

these transcendental laws of nature, and the peculiar character of

it we must make one remark, which will at the same time be important

as a guide in every other attempt to demonstrate the truth of

intellectual and likewise synthetical propositions à priori. Had we

endeavoured to prove these analogies dogmatically, that is, from

conceptions; that is to say, had we employed this method in attempting

to show that everything which exists, exists only in that which is

permanent—that every thing or event presupposes the existence of

something in a preceding state, upon which it follows in conformity

with a rule—lastly, that in the manifold, which is coexistent, the

states coexist in connection with each other according to a rule, all

our labour would have been utterly in vain. For mere conceptions of

things, analyse them as we may, cannot enable us to conclude from the

existence of one object to the existence of another. What other course

was left for us to pursue? This only, to demonstrate the possibility

of experience as a cognition in which at last all objects must be

capable of being presented to us, if the representation of them is

to possess any objective reality. Now in this third, this mediating

term, the essential form of which consists in the synthetical unity

of the apperception of all phenomena, we found à priori conditions

of the universal and necessary determination as to time of all

existences in the world of phenomena, without which the empirical

determination thereof as to time would itself be impossible, and we

also discovered rules of synthetical unity à priori, by means of

which we could anticipate experience. For want of this method, and

from the fancy that it was possible to discover a dogmatical proof

of the synthetical propositions which are requisite in the empirical

employment of the understanding, has it happened that a proof of the

principle of sufficient reason has been so often attempted, and always

in vain. The other two analogies nobody has ever thought of, although

they have always been silently employed by the mind,[34] because the

guiding thread furnished by the categories was wanting, the guide which

alone can enable us to discover every hiatus, both in the system of

conceptions and of principles.

[34] The unity of the universe, in which all phenomena to be

connected, is evidently a mere consequence of the admitted principle

of the community of all substances which are coexistent. For were

substances isolated, they could not as parts constitute a whole, and

were their connection (reciprocal action of the manifold) not

necessary from the very fact of coexistence, we could not conclude

from the fact of the latter as a merely ideal relation to the former

as a real one. We have, however, shown in its place that community is

the proper ground of the possibility of an empirical cognition of

coexistence, and that we may therefore properly reason from the latter

to the former as its condition.

4. THE POSTULATES OF EMPIRICAL THOUGHT.

1. That which agrees with the formal conditions (intuition and

conception) of experience, is possible.

2. That which coheres with the material conditions of experience

(sensation), is real.

3. That whose coherence with the real is determined according to

universal conditions of experience is (exists) necessary.

Explanation.

The categories of modality possess this peculiarity, that they do not

in the least determine the object, or enlarge the conception to which

they are annexed as predicates, but only express its relation to the

faculty of cognition. Though my conception of a thing is in itself

complete, I am still entitled to ask whether the object of it is merely

possible, or whether it is also real, or, if the latter, whether it is

also necessary. But hereby the object itself is not more definitely

determined in thought, but the question is only in what relation it,

including all its determinations, stands to the understanding and its

employment in experience, to the empirical faculty of judgement, and to

the reason of its application to experience.

For this very reason, too, the categories of modality are nothing more

than explanations of the conceptions of possibility, reality, and

necessity, as employed in experience, and at the same time,

restrictions of all the categories to empirical use alone, not

authorizing the transcendental employment of them. For if they are to

have something more than a merely logical significance, and to be

something more than a mere analytical expression of the form of

thought, and to have a relation to things and their possibility,

reality, or necessity, they must concern possible experience and its

synthetical unity, in which alone objects of cognition can be given.

The postulate of the possibility of things requires also, that the

conception of the things agree with the formal conditions of our

experience in general. But this, that is to say, the objective form of

experience, contains all the kinds of synthesis which are requisite for

the cognition of objects. A conception which contains a synthesis must

be regarded as empty and, without reference to an object, if its

synthesis does not belong to experience—either as borrowed from it, and

in this case it is called an empirical conception, or such as is the

ground and à priori condition of experience (its form), and in this

case it is a pure conception, a conception which nevertheless belongs

to experience, inasmuch as its object can be found in this alone. For

where shall we find the criterion or character of the possibility of an

object which is cogitated by means of an à priori synthetical

conception, if not in the synthesis which constitutes the form of

empirical cognition of objects? That in such a conception no

contradiction exists is indeed a necessary logical condition, but very

far from being sufficient to establish the objective reality of the

conception, that is, the possibility of such an object as is thought in

the conception. Thus, in the conception of a figure which is contained

within two straight lines, there is no contradiction, for the

conceptions of two straight lines and of their junction contain no

negation of a figure. The impossibility in such a case does not rest

upon the conception in itself, but upon the construction of it in

space, that is to say, upon the conditions of space and its

determinations. But these have themselves objective reality, that is,

they apply to possible things, because they contain à priori the form

of experience in general.

And now we shall proceed to point out the extensive utility and

influence of this postulate of possibility. When I represent to myself

a thing that is permanent, so that everything in it which changes

belongs merely to its state or condition, from such a conception alone

I never can cognize that such a thing is possible. Or, if I represent

to myself something which is so constituted that, when it is posited,

something else follows always and infallibly, my thought contains no

self-contradiction; but whether such a property as causality is to be

found in any possible thing, my thought alone affords no means of

judging. Finally, I can represent to myself different things

(substances) which are so constituted that the state or condition of

one causes a change in the state of the other, and reciprocally; but

whether such a relation is a property of things cannot be perceived

from these conceptions, which contain a merely arbitrary synthesis.

Only from the fact, therefore, that these conceptions express à priori

the relations of perceptions in every experience, do we know that they

possess objective reality, that is, transcendental truth; and that

independent of experience, though not independent of all relation to

form of an experience in general and its synthetical unity, in which

alone objects can be empirically cognized.

But when we fashion to ourselves new conceptions of substances, forces,

action, and reaction, from the material presented to us by perception,

without following the example of experience in their connection, we

create mere chimeras, of the possibility of which we cannot discover

any criterion, because we have not taken experience for our

instructress, though we have borrowed the conceptions from her. Such

fictitious conceptions derive their character of possibility not, like

the categories, à priori, as conceptions on which all experience

depends, but only, à posteriori, as conceptions given by means of

experience itself, and their possibility must either be cognized à

posteriori and empirically, or it cannot be cognized at all. A

substance which is permanently present in space, yet without filling it

(like that tertium quid between matter and the thinking subject which

some have tried to introduce into metaphysics), or a peculiar

fundamental power of the mind of intuiting the future by anticipation

(instead of merely inferring from past and present events), or,

finally, a power of the mind to place itself in community of thought

with other men, however distant they may be—these are conceptions the

possibility of which has no ground to rest upon. For they are not based

upon experience and its known laws; and, without experience, they are a

merely arbitrary conjunction of thoughts, which, though containing no

internal contradiction, has no claim to objective reality, neither,

consequently, to the possibility of such an object as is thought in

these conceptions. As far as concerns reality, it is self-evident that

we cannot cogitate such a possibility in concreto without the aid of

experience; because reality is concerned only with sensation, as the

matter of experience, and not with the form of thought, with which we

can no doubt indulge in shaping fancies.

But I pass by everything which derives its possibility from reality in

experience, and I purpose treating here merely of the possibility of

things by means of à priori conceptions. I maintain, then, that the

possibility of things is not derived from such conceptions per se, but

only when considered as formal and objective conditions of an

experience in general.

It seems, indeed, as if the possibility of a triangle could be cognized

from the conception of it alone (which is certainly independent of

experience); for we can certainly give to the conception a

corresponding object completely à priori, that is to say, we can

construct it. But as a triangle is only the form of an object, it must

remain a mere product of the imagination, and the possibility of the

existence of an object corresponding to it must remain doubtful, unless

we can discover some other ground, unless we know that the figure can

be cogitated under the conditions upon which all objects of experience

rest. Now, the facts that space is a formal condition à priori of

external experience, that the formative synthesis, by which we

construct a triangle in imagination, is the very same as that we employ

in the apprehension of a phenomenon for the purpose of making an

empirical conception of it, are what alone connect the notion of the

possibility of such a thing, with the conception of it. In the same

manner, the possibility of continuous quantities, indeed of quantities

in general, for the conceptions of them are without exception

synthetical, is never evident from the conceptions in themselves, but

only when they are considered as the formal conditions of the

determination of objects in experience. And where, indeed, should we

look for objects to correspond to our conceptions, if not in

experience, by which alone objects are presented to us? It is, however,

true that without antecedent experience we can cognize and characterize

the possibility of things, relatively to the formal conditions, under

which something is determined in experience as an object, consequently,

completely à priori. But still this is possible only in relation to

experience and within its limits.

The postulate concerning the cognition of the reality of things

requires perception, consequently conscious sensation, not indeed

immediately, that is, of the object itself, whose existence is to be

cognized, but still that the object have some connection with a real

perception, in accordance with the analogies of experience, which

exhibit all kinds of real connection in experience.

From the mere conception of a thing it is impossible to conclude its

existence. For, let the conception be ever so complete, and containing

a statement of all the determinations of the thing, the existence of it

has nothing to do with all this, but only with the question whether

such a thing is given, so that the perception of it can in every case

precede the conception. For the fact that the conception of it precedes

the perception, merely indicates the possibility of its existence; it

is perception which presents matter to the conception, that is the sole

criterion of reality. Prior to the perception of the thing, however,

and therefore comparatively à priori, we are able to cognize its

existence, provided it stands in connection with some perceptions

according to the principles of the empirical conjunction of these, that

is, in conformity with the analogies of perception. For, in this case,

the existence of the supposed thing is connected with our perception in

a possible experience, and we are able, with the guidance of these

analogies, to reason in the series of possible perceptions from a thing

which we do really perceive to the thing we do not perceive. Thus, we

cognize the existence of a magnetic matter penetrating all bodies from

the perception of the attraction of the steel-filings by the magnet,

although the constitution of our organs renders an immediate perception

of this matter impossible for us. For, according to the laws of

sensibility and the connected context of our perceptions, we should in

an experience come also on an immediate empirical intuition of this

matter, if our senses were more acute—but this obtuseness has no

influence upon and cannot alter the form of possible experience in

general. Our knowledge of the existence of things reaches as far as our

perceptions, and what may be inferred from them according to empirical

laws, extend. If we do not set out from experience, or do not proceed

according to the laws of the empirical connection of phenomena, our

pretensions to discover the existence of a thing which we do not

immediately perceive are vain. Idealism, however, brings forward

powerful objections to these rules for proving existence mediately.

This is, therefore, the proper place for its refutation.

REFUTATION OF IDEALISM.

Idealism—I mean material idealism—is the theory which declares the

existence of objects in space without us to be either () doubtful and

indemonstrable, or (2) false and impossible. The first is the

problematical idealism of Descartes, who admits the undoubted certainty

of only one empirical assertion (assertio), to wit, “I am.” The second

is the dogmatical idealism of Berkeley, who maintains that space,

together with all the objects of which it is the inseparable condition,

is a thing which is in itself impossible, and that consequently the

objects in space are mere products of the imagination. The dogmatical

theory of idealism is unavoidable, if we regard space as a property of

things in themselves; for in that case it is, with all to which it

serves as condition, a nonentity. But the foundation for this kind of

idealism we have already destroyed in the transcendental æsthetic.

Problematical idealism, which makes no such assertion, but only alleges

our incapacity to prove the existence of anything besides ourselves by

means of immediate experience, is a theory rational and evidencing a

thorough and philosophical mode of thinking, for it observes the rule

not to form a decisive judgement before sufficient proof be shown. The

desired proof must therefore demonstrate that we have experience of

external things, and not mere fancies. For this purpose, we must prove,

that our internal and, to Descartes, indubitable experience is itself

possible only under the previous assumption of external experience.

THEOREM.

The simple but empirically determined consciousness of my own existence

proves the existence of external objects in space.

PROOF

I am conscious of my own existence as determined in time. All

determination in regard to time presupposes the existence of something

permanent in perception. But this permanent something cannot be

something in me, for the very reason that my existence in time is

itself determined by this permanent something. It follows that the

perception of this permanent existence is possible only through a thing

without me and not through the mere representation of a thing without

me. Consequently, the determination of my existence in time is possible

only through the existence of real things external to me. Now,

consciousness in time is necessarily connected with the consciousness

of the possibility of this determination in time. Hence it follows that

consciousness in time is necessarily connected also with the existence

of things without me, inasmuch as the existence of these things is the

condition of determination in time. That is to say, the consciousness

of my own existence is at the same time an immediate consciousness of

the existence of other things without me.

Remark I. The reader will observe, that in the foregoing proof the game

which idealism plays is retorted upon itself, and with more justice. It

assumed that the only immediate experience is internal and that from

this we can only infer the existence of external things. But, as always

happens, when we reason from given effects to determined causes,

idealism has reasoned with too much haste and uncertainty, for it is

quite possible that the cause of our representations may lie in

ourselves, and that we ascribe it falsely to external things. But our

proof shows that external experience is properly immediate,[35] that

only by virtue of it—not, indeed, the consciousness of our own

existence, but certainly the determination of our existence in time,

that is, internal experience—is possible. It is true, that the

representation “I am,” which is the expression of the consciousness

which can accompany all my thoughts, is that which immediately includes

the existence of a subject. But in this representation we cannot find

any knowledge of the subject, and therefore also no empirical

knowledge, that is, experience. For experience contains, in addition to

the thought of something existing, intuition, and in this case it must

be internal intuition, that is, time, in relation to which the subject

must be determined. But the existence of external things is absolutely

requisite for this purpose, so that it follows that internal experience

is itself possible only mediately and through external experience.

[35] The immediate consciousness of the existence of external things

is, in the preceding theorem, not presupposed, but proved, by the

possibility of this consciousness understood by us or not. The

question as to the possibility of it would stand thus: “Have we an

internal sense, but no external sense, and is our belief in external

perception a mere delusion?” But it is evident that, in order merely

to fancy to ourselves anything as external, that is, to present it to

the sense in intuition we must already possess an external sense, and

must thereby distinguish immediately the mere receptivity of an

external intuition from the spontaneity which characterizes every act

of imagination. For merely to imagine also an external sense, would

annihilate the faculty of intuition itself which is to be determined

by the imagination.

Remark II. Now with this view all empirical use of our faculty of

cognition in the determination of time is in perfect accordance. Its

truth is supported by the fact that it is possible to perceive a

determination of time only by means of a change in external relations

(motion) to the permanent in space (for example, we become aware of the

sun’s motion by observing the changes of his relation to the objects of

this earth). But this is not all. We find that we possess nothing

permanent that can correspond and be submitted to the conception of a

substance as intuition, except matter. This idea of permanence is not

itself derived from external experience, but is an à priori necessary

condition of all determination of time, consequently also of the

internal sense in reference to our own existence, and that through the

existence of external things. In the representation “I,” the

consciousness of myself is not an intuition, but a merely intellectual

representation produced by the spontaneous activity of a thinking

subject. It follows, that this “i” has not any predicate of intuition,

which, in its character of permanence, could serve as correlate to the

determination of time in the internal sense—in the same way as

impenetrability is the correlate of matter as an empirical intuition.

Remark III. From the fact that the existence of external things is a

necessary condition of the possibility of a determined consciousness of

ourselves, it does not follow that every intuitive representation of

external things involves the existence of these things, for their

representations may very well be the mere products of the imagination

(in dreams as well as in madness); though, indeed, these are themselves

created by the reproduction of previous external perceptions, which, as

has been shown, are possible only through the reality of external

objects. The sole aim of our remarks has, however, been to prove that

internal experience in general is possible only through external

experience in general. Whether this or that supposed experience be

purely imaginary must be discovered from its particular determinations

and by comparing these with the criteria of all real experience.

Finally, as regards the third postulate, it applies to material

necessity in existence, and not to merely formal and logical necessity

in the connection of conceptions. Now as we cannot cognize completely à

priori the existence of any object of sense, though we can do so

comparatively à priori, that is, relatively to some other previously

given existence—a cognition, however, which can only be of such an

existence as must be contained in the complex of experience, of which

the previously given perception is a part—the necessity of existence

can never be cognized from conceptions, but always, on the contrary,

from its connection with that which is an object of perception. But the

only existence cognized, under the condition of other given phenomena,

as necessary, is the existence of effects from given causes in

conformity with the laws of causality. It is consequently not the

necessity of the existence of things (as substances), but the necessity

of the state of things that we cognize, and that not immediately, but

by means of the existence of other states given in perception,

according to empirical laws of causality. Hence it follows that the

criterion of necessity is to be found only in the law of possible

experience—that everything which happens is determined à priori in the

phenomenon by its cause. Thus we cognize only the necessity of effects

in nature, the causes of which are given us. Moreover, the criterion of

necessity in existence possesses no application beyond the field of

possible experience, and even in this it is not valid of the existence

of things as substances, because these can never be considered as

empirical effects, or as something that happens and has a beginning.

Necessity, therefore, regards only the relations of phenomena according

to the dynamical law of causality, and the possibility grounded

thereon, of reasoning from some given existence (of a cause) à priori

to another existence (of an effect). “Everything that happens is

hypothetically necessary,” is a principle which subjects the changes

that take place in the world to a law, that is, to a rule of necessary

existence, without which nature herself could not possibly exist. Hence

the proposition, “Nothing happens by blind chance (in mundo non datur

casus),” is an à priori law of nature. The case is the same with the

proposition, “Necessity in nature is not blind,” that is, it is

conditioned, consequently intelligible necessity (non datur fatum).

Both laws subject the play of change to “a nature of things (as

phenomena),” or, which is the same thing, to the unity of the

understanding, and through the understanding alone can changes belong

to an experience, as the synthetical unity of phenomena. Both belong to

the class of dynamical principles. The former is properly a consequence

of the principle of causality—one of the analogies of experience. The

latter belongs to the principles of modality, which to the

determination of causality adds the conception of necessity, which is

itself, however, subject to a rule of the understanding. The principle

of continuity forbids any leap in the series of phenomena regarded as

changes (in mundo non datur saltus); and likewise, in the complex of

all empirical intuitions in space, any break or hiatus between two

phenomena (non datur hiatus)—for we can so express the principle, that

experience can admit nothing which proves the existence of a vacuum, or

which even admits it as a part of an empirical synthesis. For, as

regards a vacuum or void, which we may cogitate as out and beyond the

field of possible experience (the world), such a question cannot come

before the tribunal of mere understanding, which decides only upon

questions that concern the employment of given phenomena for the

construction of empirical cognition. It is rather a problem for ideal

reason, which passes beyond the sphere of a possible experience and

aims at forming a judgement of that which surrounds and circumscribes

it, and the proper place for the consideration of it is the

transcendental dialectic. These four propositions, “In mundo non datur

hiatus, non datur saltus, non datur casus, non datur fatum,” as well as

all principles of transcendental origin, we could very easily exhibit

in their proper order, that is, in conformity with the order of the

categories, and assign to each its proper place. But the already

practised reader will do this for himself, or discover the clue to such

an arrangement. But the combined result of all is simply this, to admit

into the empirical synthesis nothing which might cause a break in or be

foreign to the understanding and the continuous connection of all

phenomena, that is, the unity of the conceptions of the understanding.

For in the understanding alone is the unity of experience, in which all

perceptions must have their assigned place, possible.

Whether the field of possibility be greater than that of reality, and

whether the field of the latter be itself greater than that of

necessity, are interesting enough questions, and quite capable of

synthetic solution, questions, however, which come under the

jurisdiction of reason alone. For they are tantamount to asking whether

all things as phenomena do without exception belong to the complex and

connected whole of a single experience, of which every given perception

is a part which therefore cannot be conjoined with any other

phenomena—or, whether my perceptions can belong to more than one

possible experience? The understanding gives to experience, according

to the subjective and formal conditions, of sensibility as well as of

apperception, the rules which alone make this experience possible.

Other forms of intuition besides those of space and time, other forms

of understanding besides the discursive forms of thought, or of

cognition by means of conceptions, we can neither imagine nor make

intelligible to ourselves; and even if we could, they would still not

belong to experience, which is the only mode of cognition by which

objects are presented to us. Whether other perceptions besides those

which belong to the total of our possible experience, and consequently

whether some other sphere of matter exists, the understanding has no

power to decide, its proper occupation being with the synthesis of that

which is given. Moreover, the poverty of the usual arguments which go

to prove the existence of a vast sphere of possibility, of which all

that is real (every object of experience) is but a small part, is very

remarkable. “All real is possible”; from this follows naturally,

according to the logical laws of conversion, the particular

proposition: “Some possible is real.” Now this seems to be equivalent

to: “Much is possible that is not real.” No doubt it does seem as if we

ought to consider the sum of the possible to be greater than that of

the real, from the fact that something must be added to the former to

constitute the latter. But this notion of adding to the possible is

absurd. For that which is not in the sum of the possible, and

consequently requires to be added to it, is manifestly impossible. In

addition to accordance with the formal conditions of experience, the

understanding requires a connection with some perception; but that

which is connected with this perception is real, even although it is

not immediately perceived. But that another series of phenomena, in

complete coherence with that which is given in perception, consequently

more than one all-embracing experience is possible, is an inference

which cannot be concluded from the data given us by experience, and

still less without any data at all. That which is possible only under

conditions which are themselves merely possible, is not possible in any

respect. And yet we can find no more certain ground on which to base

the discussion of the question whether the sphere of possibility is

wider than that of experience.

I have merely mentioned these questions, that in treating of the

conception of the understanding, there might be no omission of anything

that, in the common opinion, belongs to them. In reality, however, the

notion of absolute possibility (possibility which is valid in every

respect) is not a mere conception of the understanding, which can be

employed empirically, but belongs to reason alone, which passes the

bounds of all empirical use of the understanding. We have, therefore,

contented ourselves with a merely critical remark, leaving the subject

to be explained in the sequel.

Before concluding this fourth section, and at the same time the system

of all principles of the pure understanding, it seems proper to mention

the reasons which induced me to term the principles of modality

postulates. This expression I do not here use in the sense which some

more recent philosophers, contrary to its meaning with mathematicians,

to whom the word properly belongs, attach to it—that of a proposition,

namely, immediately certain, requiring neither deduction nor proof. For

if, in the case of synthetical propositions, however evident they may

be, we accord to them without deduction, and merely on the strength of

their own pretensions, unqualified belief, all critique of the

understanding is entirely lost; and, as there is no want of bold

pretensions, which the common belief (though for the philosopher this

is no credential) does not reject, the understanding lies exposed to

every delusion and conceit, without the power of refusing its assent to

those assertions, which, though illegitimate, demand acceptance as

veritable axioms. When, therefore, to the conception of a thing an à

priori determination is synthetically added, such a proposition must

obtain, if not a proof, at least a deduction of the legitimacy of its

assertion.

The principles of modality are, however, not objectively synthetical,

for the predicates of possibility, reality, and necessity do not in the

least augment the conception of that of which they are affirmed,

inasmuch as they contribute nothing to the representation of the

object. But as they are, nevertheless, always synthetical, they are so

merely subjectively. That is to say, they have a reflective power, and

apply to the conception of a thing, of which, in other respects, they

affirm nothing, the faculty of cognition in which the conception

originates and has its seat. So that if the conception merely agree

with the formal conditions of experience, its object is called

possible; if it is in connection with perception, and determined

thereby, the object is real; if it is determined according to

conceptions by means of the connection of perceptions, the object is

called necessary. The principles of modality therefore predicate of a

conception nothing more than the procedure of the faculty of cognition

which generated it. Now a postulate in mathematics is a practical

proposition which contains nothing but the synthesis by which we

present an object to ourselves, and produce the conception of it, for

example—“With a given line, to describe a circle upon a plane, from a

given point”; and such a proposition does not admit of proof, because

the procedure, which it requires, is exactly that by which alone it is

possible to generate the conception of such a figure. With the same

right, accordingly, can we postulate the principles of modality,

because they do not augment[36] the conception of a thing but merely

indicate the manner in which it is connected with the faculty of

cognition.

[36] When I think the reality of a thing, I do really think more than

the possibility, but not in the thing; for that can never contain more

in reality than was contained in its complete possibility. But while

the notion of possibility is merely the notion of a position of thing

in relation to the understanding (its empirical use), reality is the

conjunction of the thing with perception.

GENERAL REMARK ON THE SYSTEM OF PRINCIPLES.

It is very remarkable that we cannot perceive the possibility of a

thing from the category alone, but must always have an intuition, by

which to make evident the objective reality of the pure conception of

the understanding. Take, for example, the categories of relation. How

(1) a thing can exist only as a subject, and not as a mere

determination of other things, that is, can be substance; or how (2),

because something exists, some other thing must exist, consequently how

a thing can be a cause; or how (3), when several things exist, from the

fact that one of these things exists, some consequence to the others

follows, and reciprocally, and in this way a community of substances

can be possible—are questions whose solution cannot be obtained from

mere conceptions. The very same is the case with the other categories;

for example, how a thing can be of the same sort with many others, that

is, can be a quantity, and so on. So long as we have not intuition we

cannot know whether we do really think an object by the categories, and

where an object can anywhere be found to cohere with them, and thus the

truth is established, that the categories are not in themselves

cognitions, but mere forms of thought for the construction of

cognitions from given intuitions. For the same reason is it true that

from categories alone no synthetical proposition can be made. For

example: “In every existence there is substance,” that is, something

that can exist only as a subject and not as mere predicate; or,

“Everything is a quantity”—to construct propositions such as these, we

require something to enable us to go out beyond the given conception

and connect another with it. For the same reason the attempt to prove a

synthetical proposition by means of mere conceptions, for example:

“Everything that exists contingently has a cause,” has never succeeded.

We could never get further than proving that, without this relation to

conceptions, we could not conceive the existence of the contingent,

that is, could not à priori through the understanding cognize the

existence of such a thing; but it does not hence follow that this is

also the condition of the possibility of the thing itself that is said

to be contingent. If, accordingly; we look back to our proof of the

principle of causality, we shall find that we were able to prove it as

valid only of objects of possible experience, and, indeed, only as

itself the principle of the possibility of experience, Consequently of

the cognition of an object given in empirical intuition, and not from

mere conceptions. That, however, the proposition: “Everything that is

contingent must have a cause,” is evident to every one merely from

conceptions, is not to be denied. But in this case the conception of

the contingent is cogitated as involving not the category of modality

(as that the non-existence of which can be conceived) but that of

relation (as that which can exist only as the consequence of something

else), and so it is really an identical proposition: “That which can

exist only as a consequence, has a cause.” In fact, when we have to

give examples of contingent existence, we always refer to changes, and

not merely to the possibility of conceiving the opposite.[37] But

change is an event, which, as such, is possible only through a cause,

and considered per se its non-existence is therefore possible, and we

become cognizant of its contingency from the fact that it can exist

only as the effect of a cause. Hence, if a thing is assumed to be

contingent, it is an analytical proposition to say, it has a cause.

[37] We can easily conceive the non-existence of matter; but the

ancients did not thence infer its contingency. But even the

alternation of the existence and non-existence of a given state in a

thing, in which all change consists, by no means proves the

contingency of that state—the ground of proof being the reality of its

opposite. For example, a body is in a state of rest after motion, but

we cannot infer the contingency of the motion from the fact that the

former is the opposite of the latter. For this opposite is merely a

logical and not a real opposite to the other. If we wish to

demonstrate the contingency of the motion, what we ought to prove is

that, instead of the motion which took place in the preceding point of

time, it was possible for the body to have been then in rest, not,

that it is afterwards in rest; for in this case, both opposites are

perfectly consistent with each other.

But it is still more remarkable that, to understand the possibility of

things according to the categories and thus to demonstrate the

objective reality of the latter, we require not merely intuitions, but

external intuitions. If, for example, we take the pure conceptions of

relation, we find that (1) for the purpose of presenting to the

conception of substance something permanent in intuition corresponding

thereto and thus of demonstrating the objective reality of this

conception, we require an intuition (of matter) in space, because space

alone is permanent and determines things as such, while time, and with

it all that is in the internal sense, is in a state of continual flow;

(2) in order to represent change as the intuition corresponding to the

conception of causality, we require the representation of motion as

change in space; in fact, it is through it alone that changes, the

possibility of which no pure understanding can perceive, are capable of

being intuited. Change is the connection of determinations

contradictorily opposed to each other in the existence of one and the

same thing. Now, how it is possible that out of a given state one quite

opposite to it in the same thing should follow, reason without an

example can not only not conceive, but cannot even make intelligible

without intuition; and this intuition is the motion of a point in

space; the existence of which in different spaces (as a consequence of

opposite determinations) alone makes the intuition of change possible.

For, in order to make even internal change cognitable, we require to

represent time, as the form of the internal sense, figuratively by a

line, and the internal change by the drawing of that line (motion), and

consequently are obliged to employ external intuition to be able to

represent the successive existence of ourselves in different states.

The proper ground of this fact is that all change to be perceived as

change presupposes something permanent in intuition, while in the

internal sense no permanent intuition is to be found. Lastly, the

objective possibility of the category of community cannot be conceived

by mere reason, and consequently its objective reality cannot be

demonstrated without an intuition, and that external in space. For how

can we conceive the possibility of community, that is, when several

substances exist, that some effect on the existence of the one follows

from the existence of the other, and reciprocally, and therefore that,

because something exists in the latter, something else must exist in

the former, which could not be understood from its own existence alone?

For this is the very essence of community—which is inconceivable as a

property of things which are perfectly isolated. Hence, Leibnitz, in

attributing to the substances of the world—as cogitated by the

understanding alone—a community, required the mediating aid of a

divinity; for, from their existence, such a property seemed to him with

justice inconceivable. But we can very easily conceive the possibility

of community (of substances as phenomena) if we represent them to

ourselves as in space, consequently in external intuition. For external

intuition contains in itself à priori formal external relations, as the

conditions of the possibility of the real relations of action and

reaction, and therefore of the possibility of community. With the same

ease can it be demonstrated, that the possibility of things as

quantities, and consequently the objective reality of the category of

quantity, can be grounded only in external intuition, and that by its

means alone is the notion of quantity appropriated by the internal

sense. But I must avoid prolixity, and leave the task of illustrating

this by examples to the reader’s own reflection.

The above remarks are of the greatest importance, not only for the

confirmation of our previous confutation of idealism, but still more

when the subject of self-cognition by mere internal consciousness and

the determination of our own nature without the aid of external

empirical intuitions is under discussion, for the indication of the

grounds of the possibility of such a cognition.

The result of the whole of this part of the analytic of principles is,

therefore: “All principles of the pure understanding are nothing more

than à priori principles of the possibility of experience, and to

experience alone do all à priori synthetical propositions apply and

relate”; indeed, their possibility itself rests entirely on this

relation.

Chapter III Of the Ground of the Division of all Objects into Phenomena

and Noumena

We have now not only traversed the region of the pure understanding and

carefully surveyed every part of it, but we have also measured it, and

assigned to everything therein its proper place. But this land is an

island, and enclosed by nature herself within unchangeable limits. It

is the land of truth (an attractive word), surrounded by a wide and

stormy ocean, the region of illusion, where many a fog-bank, many an

iceberg, seems to the mariner, on his voyage of discovery, a new

country, and, while constantly deluding him with vain hopes, engages

him in dangerous adventures, from which he never can desist, and which

yet he never can bring to a termination. But before venturing upon this

sea, in order to explore it in its whole extent, and to arrive at a

certainty whether anything is to be discovered there, it will not be

without advantage if we cast our eyes upon the chart of the land that

we are about to leave, and to ask ourselves, firstly, whether we cannot

rest perfectly contented with what it contains, or whether we must not

of necessity be contented with it, if we can find nowhere else a solid

foundation to build upon; and, secondly, by what title we possess this

land itself, and how we hold it secure against all hostile claims?

Although, in the course of our analytic, we have already given

sufficient answers to these questions, yet a summary recapitulation of

these solutions may be useful in strengthening our conviction, by

uniting in one point the momenta of the arguments.

We have seen that everything which the understanding draws from itself,

without borrowing from experience, it nevertheless possesses only for

the behoof and use of experience. The principles of the pure

understanding, whether constitutive à priori (as the mathematical

principles), or merely regulative (as the dynamical), contain nothing

but the pure schema, as it were, of possible experience. For experience

possesses its unity from the synthetical unity which the understanding,

originally and from itself, imparts to the synthesis of the imagination

in relation to apperception, and in à priori relation to and agreement

with which phenomena, as data for a possible cognition, must stand. But

although these rules of the understanding are not only à priori true,

but the very source of all truth, that is, of the accordance of our

cognition with objects, and on this ground, that they contain the basis

of the possibility of experience, as the ensemble of all cognition, it

seems to us not enough to propound what is true—we desire also to be

told what we want to know. If, then, we learn nothing more by this

critical examination than what we should have practised in the merely

empirical use of the understanding, without any such subtle inquiry,

the presumption is that the advantage we reap from it is not worth the

labour bestowed upon it. It may certainly be answered that no rash

curiosity is more prejudicial to the enlargement of our knowledge than

that which must know beforehand the utility of this or that piece of

information which we seek, before we have entered on the needful

investigations, and before one could form the least conception of its

utility, even though it were placed before our eyes. But there is one

advantage in such transcendental inquiries which can be made

comprehensible to the dullest and most reluctant learner—this, namely,

that the understanding which is occupied merely with empirical

exercise, and does not reflect on the sources of its own cognition, may

exercise its functions very well and very successfully, but is quite

unable to do one thing, and that of very great importance, to

determine, namely, the bounds that limit its employment, and to know

what lies within or without its own sphere. This purpose can be

obtained only by such profound investigations as we have instituted.

But if it cannot distinguish whether certain questions lie within its

horizon or not, it can never be sure either as to its claims or

possessions, but must lay its account with many humiliating

corrections, when it transgresses, as it unavoidably will, the limits

of its own territory, and loses itself in fanciful opinions and

blinding illusions.