The Online Library of Liberty

A project of Liberty Fund, Inc.

• Dedication
• Preface 1
• Translator’s Preface
• Translator’s Preface to Second Edition
• Introduction [p. 1]
• I: The Idea of Transcendental Philosophy
• II: Division of Transcendental Philosophy
• I: The Elements of Transcendentalism
• Part I: Transcendental Æsthetic [p. 19]
• Section I: Of Space
• Section II: Of Time
• Part II: Transcendental Logic [p. 50]
• Introduction the 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
• Division I: Transcendental Analytic In Two Books, With Their Chapters and Sections
• Book I: Analytic of Concepts
• Chapter I: Method of Discovering All Pure Concepts of the Understanding
• Section I: Of the Logical Use of the Understanding In General
• Section II: Of the Logical Function of the Understanding In Judgments [p. 70]
• Section III: Of the Pure Concepts of the Understanding, Or of the Categories
• Chapter II: Of the Deduction of the Pure Concepts of the Understanding [p. 84]
• Section I: Of the Principles of a Transcendental Deduction In General
• Section II: Of the a Priori Grounds For the Possibility of Experience
• I: Of the Synthesis of Apprehension In Intuition
• II: Of the Synthesis of Reproduction In Imagination
• III: Of the Synthesis of Recognition In Concepts [p. 103]
• IV: Preliminary Explanation of the Possibility of the Categories As Knowledge a Priori
• Section III: Of the Relation of the Understanding to Objects In General, and the Possibility of Knowing Them a Priori [p. 115]
• Book II: Analytic of Principles
• Introduction of the Transcendental Faculty of Judgment In General
• Chapter I: Of the Schematism of the Pure Concepts of the Understanding [p. 137]
• Chapter II: System of All Principles of the Pure Understanding [p. 148]
• Section I: Of the Highest Principle of All Analytical Judgments
• Section II: Of the Highest Principle of All Synthetical Judgments [p. 154]
• Section III: Systematical Representation of All Synthetical Principles of the Understanding
• I: [of the Axioms of Intuition 1 Principle of the Pure Understanding
• II: [ Anticipations of Perception
• III: [ the Analogies of Experience
• IV: The Postulates of Empirical Thought In General
• Chapter III: On the Ground of Distinction of All Subjects Into Phenomena and Noumena
• I.: Identity and Difference
• II.: Agreement and Opposition
• III.: The Internal and the External
• IV.: Matter and Form
• Note On the Amphiboly of Reflective Concepts
• Division II: Transcendental Dialectic In Two Books, With Their Chapters and Sections [p. 293]
• Introduction: 1.
• Book I: Of the Concepts of Pure Reason [p. 310]
• First Section of Ideas In General
• Second Section of Transcendental Ideas [p. 321]
• Third Section System of Transcendental Ideas [p. 333]
• Book II: Of the Dialectical Conclusions of Pure Reason
• Chapter I: Of the Paralogisms of Pure Reason [p. 341]
• 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 Conflicts [p. 462]
• Section IV: Of the Transcendental Problems of Pure Reason, and the Absolute Necessity of Their Solution
• Section V: Sceptical Representation of the Cosmological Questions In the Four Transcendental Ideas [p. 485]
• Section VI: Transcendental Idealism As the Key to the Solution of Cosmological Dialectic
• Section VII: Critical Decision of the Cosmological Conflict of Reason With Itself
• Section VIII: The Regulative Principle of Pure Reason With Regard to the Cosmological Ideas [p. 508]
• Section IX: Of the Empirical Use of the Regulative Principle of Reason With Regard to All Cosmological Ideas
• Chapter III: The Ideal of Pure Reason
• Section I: Of the Ideal In General
• Section II: Of the Transcendental Ideal ( Prototypon Transcendentale )
• Section III: Of the Arguments of 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 [p. 592]
• Section V: Of the Impossibility of a Cosmological Proof of the Existence of God [p. 603]
• Section VI: Of the Impossibility of the Physico-theological Proof
• Section VII: Criticism of All Theology Based On Speculative Principles of Reason [p. 631]
• Chapter I: The Discipline of Pure Reason
• Section I: The Discipline of Pure Reason In Its Dogmatical Use
• Section II: The Discipline of Pure Reason In Its Polemical Use
• Section III: The Discipline of Pure Reason With Regard to Hypotheses
• Section IV: The Discipline of Pure Reason With Regard to Its Proofs
• Chapter II: The Canon of Pure Reason [p. 795]
• First Section: of the Ultimate Aim of the Pure Use of Our Reason
• Section II: Of the Ideal of the Summum Bonum As Determining the Ultimate Aim of Pure Reason
• Section III: Of Trowing, Knowing, and Believing [p. 820]
• Chapter III: The Architectonic of Pure Reason [p. 832]
• Chapter IV: The History of Pure Reason [p. 852]
• Supplement I: Motto to Second Edition
• Supplement II: Preface to the Second Edition. 1787. [p. Vii]
• Supplement III: Supplement Iv
• Supplement V
• Supplement Vi
• Supplement V
• Supplement Vi
• Supplement Vii
• Supplement Viii
• Supplement Ix
• Supplement X
• Supplement Xi
• Supplement Xii
• Supplement Xiii
• Supplement Xiv
• Supplement Xv
• Supplement Xvi a
• Supplement Xvi B
• Supplement Xvii
• Supplement Xviii
• Supplement Xix
• Supplement Xx
• Supplement Xxi
• Supplement Xxii
• Supplement Xxiii
• Supplement Xxiv
• Supplement Xxv
• Supplement Xxvi
• Supplement Xxvii
• Supplement Xxviii

PART I

Transcendental Æsthetic [p. 19]

Whatever the process and the means may be by which knowledge reaches its objects, there is one that reaches them directly, and forms the ultimate material of all thought, viz. intuition (Anschauung). This is possible only when the object is given, and the object can be given only (to human beings at least) through a certain affection of the mind (Gemüth).

This faculty (receptivity) of receiving representations (Vorstellungen), according to the manner in which we are affected by objects, is called sensibility (Sinnlichkeit).

Objects therefore are given to us through our sensibility. Sensibility alone supplies us with intuitions (Anschauungen). These intuitions become thought through the understanding (Verstand), and hence arise conceptions (Begriffe). All thought therefore must, directly or indirectly, go back to intuitions (Anschauungen), i.e. to our sensibility, because in no other way can objects be given to us.

The effect produced by an object upon the fancy of representation (Vorstellungsfähigkeit), so far as we [p. 20] are affected by it, is called sensation (Empfindung). An intuition (Anschauung) of an object, by means of sensation, is called empirical. The undefined object of such an empirical intuition is called phenomenon (Erscheinung).

In a phenomenon I call that which corresponds to the sensation its matter; but that which causes the manifold matter of the phenomenon to be perceived as arranged in a certain order, I call its form.

Now it is clear that it cannot be sensation again through which sensations are arranged and placed in certain forms. The matter only of all phenomena is given us a posteriori; but their form must be ready for them in the mind (Gemüth) a priori, and must therefore be capable of being considered as separate from all sensations.

I call all representations in which there is nothing that belongs to sensation, pure (in a transcendental sense). The pure form therefore of all sensuous intuitions, that form in which the manifold elements of the phenomena are seen in a certain order, must be found in the mind a priori. And this pure form of sensibility may be called the pure intuition (Anschauung).

Thus, if we deduct from the representation (Vorstellung) of a body what belongs to the thinking of the understanding, viz. substance, force, divisibility, etc., and likewise what belongs to sensation, viz. impermeability, hardness, colour, etc., there still remains something [p. 21] of that empirical intuition (Anschauung), viz. extension and form. These belong to pure intuition, which a priori, and even without a real object of the senses or of sensation, exists in the mind as a mere form of sensibility.

The science of all the principles of sensibility a priori I call Transcendental Æsthetic.1 There must be such a science, forming the first part of the Elements of Transcendentalism, as opposed to that which treats of the principles of pure thought, and which should be called Transcendental Logic.

In Transcendental Æsthetic therefore we shall [p. 22] first isolate sensibility, by separating everything which the understanding adds by means of its concepts, so that nothing remains but empirical intuition (Anschauung).

Secondly, we shall separate from this all that belongs to sensation (Empfindung), so that nothing remains but pure intuition (reine Anschauung) or the mere form of the phenomena, which is the only thing which sensibility a priori can supply. In the course of this investigation it will appear that there are, as principles of a priori knowledge, two pure forms of sensuous intuition (Anschauung), namely, Space and Time. We now proceed to consider these more in detail.

Section I

Of Space

By means of our external sense, a property of our mind (Gemüth), we represent to ourselves objects as external or outside ourselves, and all of these in space. It is within space that their form, size, and relative position are fixed or can be fixed. The internal sense by means of which the mind perceives itself or its internal state, does not give an intuition (Anschauung) of the soul (Seele) itself, as an object, but it is nevertheless a fixed form under which alone an intuition of its internal state is [p. 23] possible, so that whatever belongs to its internal determinations (Bestimmungen) must be represented in relations of time. Time cannot be perceived (angeschaut) externally, as little as space can be perceived as something within us.

What then are space and time? Are they real beings? Or, if not that, are they determinations or relations of things, but such as would belong to them even if they were not perceived? Or lastly, are they determinations and relations which are inherent in the form of intuition only, and therefore in the subjective nature of our mind, without which such predicates as space and time would never be ascribed to anything?

In order to understand this more clearly, let us first consider space.

1. Space is not an empirical concept which has been derived from external experience. For in order that certain sensations should be referred to something outside myself, i.e. to something in a different part of space from that where I am; again, in order that I may be able to represent them (vorstellen) as side by side, that is, not only as different, but as in different places, the representation (Vorstellung) of space must already be there. Therefore the representation of space cannot be borrowed through experience from relations of external phenomena, but, on the contrary, this external experience becomes possible only by means of the representation of space.

2. Space is a necessary representation a priori, forming the very foundation of all external intuitions. [p. 24] It is impossible to imagine that there should be no space, though one might very well imagine that there should be space without objects to fill it. Space is therefore regarded as a condition of the possibility of phenomena, not as a determination produced by them; it is a representation a priori which necessarily precedes all external phenomena.

[3. On this necessity of an a priori representation of space rests the apodictic certainty of all geometrical principles, and the possibility of their construction a priori. For if the intuition of space were a concept gained a posteriori, borrowed from general external experience, the first principles of mathematical definition would be nothing but perceptions. They would be exposed to all the accidents of perception, and there being but one straight line between two points would not be a necessity, but only something taught in each case by experience. Whatever is derived from experience possesses a relative generality only, based on induction. We should therefore not be able to say more than that, so far as hitherto observed, no space has yet been found having more than three dimensions.]

4. Space is not a discursive or so-called general [p. 25] concept of the relations of things in general, but a pure intuition. For, first of all, we can imagine one space only and if we speak of many spaces, we mean parts only of one and the same space. Nor can these parts be considered as antecedent to the one and all-embracing space and, as it were, its component parts out of which an aggregate is formed, but they can be thought of as existing within it only. Space is essentially one; its multiplicity, and therefore the general concept of spaces in general, arises entirely from limitations. Hence it follows that, with respect to space, an intuition a priori, which is not empirical, must form the foundation of all conceptions of space. In the same manner all geometrical principles, e.g. ‘that in every triangle two sides together are greater than the third,’ are never to be derived from the general concepts of side and triangle, but from an intuition, and that a priori, with apodictic certainty.

[5. Space is represented as an infinite quantity. Now a general concept of space, which is found in a foot as well as in an ell, could tell us nothing in respect to the quantity of the space. If there were not infinity in the progression of intuition, no concept of relations of space could ever contain a principle of infinity.1 ]

Conclusions from the Foregoing Concepts [p. 26]

a. Space does not represent any quality of objects by themselves, or objects in their relation to one another; i.e. space does not represent any determination which is inherent in the objects themselves, and would remain, even if all subjective conditions of intuition were removed. For no determinations of objects, whether belonging to them absolutely or in relation to others, can enter into our intuition before the actual existence of the objects themselves, that is to say, they can never be intuitions a priori.

b. Space is nothing but the form of all phenomena of the external senses; it is the subjective condition of our sensibility, without which no external intuition is possible for us. If then we consider that the receptivity of the subject, its capacity of being affected by objects, must necessarily precede all intuition of objects, we shall understand how the form of all phenomena may be given before all real perceptions, may be, in fact, a priori in the soul, and may, as a pure intuition, by which all objects must be determined, contain, prior to all experience, principles regulating their relations.

It is therefore from the human standpoint only that we can speak of space, extended objects, etc. If we drop the subjective condition under which alone we can gain external intuition, that is, so far as we ourselves may be affected by objects, the representation of space means nothing. For this predicate is applied to objects only in so far as they appear to us, and are objects of our [p. 27] senses. The constant form of this receptivity, which we call sensibility, is a necessary condition of all relations in which objects, as without us, can be perceived; and, when abstraction is made of these objects, what remains is that pure intuition which we call space. As the peculiar conditions of our sensibility cannot be looked upon as conditions of the possibility of the objects themselves, but only of their appearance as phenomena to us, we may say indeed that space comprehends all things which may appear to us externally, but not all things by themselves, whether perceived by us or not, or by any subject whatsoever. We cannot judge whether the intuitions of other thinking beings are subject to the same conditions which determine our intuition, and which for us are generally binding. If we add the limitation of a judgment to a subjective concept, the judgment gains absolute validity. The proposition ‘all things are beside each other in space,’ is valid only under the limitation that things are taken as objects of our sensuous intuition (Anschauung). If I add that limitation to the concept and say ‘all things, as external phenomena, are beside each other in space,’ the rule obtains universal and unlimited validity. Our discussions teach therefore the reality, i.e. the objective validity, of space with regard to all that can come to us externally [p. 28] as an object, but likewise the ideality of space with regard to things, when they are considered in themselves by our reason, and independent of the nature of our senses. We maintain the empirical reality of space, so far as every possible external experience is concerned, but at the same time its transcendental ideality; that is to say, we maintain that space is nothing, if we leave out of consideration the condition of a possible experience, and accept it as something on which things by themselves are in any way dependent.

With the exception of space there is no other subjective representation (Vorstellung) referring to something external, that would be called a priori objective. [This1 subjective condition of all external phenomena cannot therefore be compared to any other. The taste of wine does not belong to the objective determinations of wine, considered as an object, even as a phenomenal object, but to the peculiar nature of the sense belonging to the subject that tastes the wine. Colours are not qualities of a body, though inherent in its intuition, but they are likewise modifications only of the sense of sight, as it is affected in different ways by light. Space, on the contrary, as the very condition of external objects, is essential to their appearance or intuition. Taste and colour are by no means necessary conditions under which alone things [p. 29] can become to us objects of sensuous perception. They are connected with their appearance, as accidentally added effects only of our peculiar organisation. They are not therefore representations a priori, but are dependent on sensation (Empfindung), nay taste even on an affection (Gefühl) of pleasure and pain, which is the result of a sensation. No one can have a priori, an idea (Vorstellung) either of colour or of taste, but space refers to the pure form of intuition only, and involves no kind of sensation, nothing empirical; nay all kinds and determinations of space can and must be represented a priori, if concepts of forms and their relations are to arise. Through it alone is it possible that things should become external objects to us.]

My object in what I have said just now is only to prevent people from imagining that they can elucidate the ideality of space by illustrations which are altogether insufficient, such as colour, taste, etc., which should never be considered as qualities of things, but as modifications of the subject, and which therefore may be different with different people. For in this case that which originally is itself a phenomenon only, as for instance, a rose, is taken by the empirical understanding for a thing by itself, which nevertheless, with regard to colour, may appear [p. 30] different to every eye. The transcendental conception, on the contrary, of all phenomena in space, is a critical warning that nothing which is seen in space is a thing by itself, nor space a form of things supposed to belong to them by themselves, but that objects by themselves are not known to us at all, and that what we call external objects are nothing but representations of our senses, the form of which is space, and the true correlative of which, that is the thing by itself, is not known, nor can be known by these representations, nor do we care to know anything about it in our daily experience.1

Section II

Of Time

I. Time is not an empirical concept deduced from any experience, for neither coexistence nor succession would enter into our perception, if the representation of time were not given a priori. Only when this representation a priori is given, can we imagine that certain things happen at the same time (simultaneously) or at different times (successively). [p. 31]

II. Time is a necessary representation on which all intuitions depend. We cannot take away time from phenomena in general, though we can well take away phenomena out of time. Time therefore is given a priori. In time alone is reality of phenomena possible. All phenomena may vanish, but time itself (as the general condition of their possibility) cannot be done away with.

III. On this a priori necessity depends also the possibility of apodictic principles of the relations of time, or of axioms of time in general. Time has one dimension only; different times are not simultaneous, but successive, while different spaces are never successive, but simultaneous. Such principles cannot be derived from experience, because experience could not impart to them absolute universality nor apodictic certainty. We should only be able to say that common experience teaches us that it is so, but not that it must be so. These principles are valid as rules under which alone experience is possible; they teach us before experience, not by means of experience.1

IV. Time is not a discursive, or what is called a general concept, but a pure form of sensuous intuition. Different times are parts only of one and the same time. Representation, which can be produced by a single [p. 32] object only, is called an intuition. The proposition that different times cannot exist at the same time cannot be deduced from any general concept. Such a proposition is synthetical, and cannot be deduced from concepts only. It is contained immediately in the intuition and representation of time.

V. To say that time is infinite means no more than that every definite quantity of time is possible only by limitations of one time which forms the foundation of all times. The original representation of time must therefore be given as unlimited. But when the parts themselves and every quantity of an object can be represented as determined by limitation only, the whole representation cannot be given by concepts (for in that case the partial representations come first), but it must be founded on immediate intuition.1

Conclusions from the foregoing concepts

a. Time is not something existing by itself, or inherent in things as an objective determination of them, something therefore that might remain when abstraction is made of all subjective conditions of intuition. For in the former case it would be something real, without being a real object. In the latter it could not, as a determination [p. 33] or order inherent in things themselves, be antecedent to things as their condition, and be known and perceived by means of synthetical propositions a priori. All this is perfectly possible if time is nothing but a subjective condition under which alone2 intuitions take place within us. For in that case this form of internal intuition can be represented prior to the objects themselves, that is, a priori.

b. Time is nothing but the form of the internal sense, that is, of our intuition of ourselves, and of our internal state. Time cannot be a determination peculiar to external phenomena. It refers neither to their shape, nor their position, etc., it only determines the relation of representations in our internal state. And exactly because this internal intuition supplies no shape, we try to make good this deficiency by means of analogies, and represent to ourselves the succession of time by a line progressing to infinity, in which the manifold constitutes a series of one dimension only; and we conclude from the properties of this line as to all the properties of time, with one exception, i.e. that the parts of the former are simultaneous, those of the latter successive. From this it becomes clear also, that the representation of time is itself an intuition, because all its relations can be expressed by means of an external intuition.

c. Time is the formal condition, a priori, of all phenomena whatsoever. Space, as the pure form of all [p. 34] external intuition, is a condition, a priori, of external phenomena only. But, as all representations, whether they have for their objects external things or not, belong by themselves, as determinations of the mind, to our inner state, and as this inner state falls under the formal conditions of internal intuition, and therefore of time, time is a condition, a priori, of all phenomena whatsoever, and is so directly as a condition of internal phenomena (of our mind) and thereby indirectly of external phenomena also. If I am able to say, a priori, that all external phenomena are in space, and are determined, a priori, according to the relations of space, I can, according to the principle of the internal sense, make the general assertion that all phenomena, that is, all objects of the senses, are in time, and stand necessarily in relations of time.

If we drop our manner of looking at ourselves internally, and of comprehending by means of that intuition all external intuitions also within our power of representation, and thus take objects as they may be by themselves, then time is nothing. Time has objective validity with reference to phenomena only, because these are themselves things which we accept as objects of our senses; but time is no longer objective, if we [p. 35] remove the sensuous character of our intuitions, that is to say, that mode of representation which is peculiar to ourselves, and speak of things in general. Time is therefore simply a subjective condition of our (human) intuition (which is always sensuous, that is so far as we are affected by objects), but by itself, apart from the subject, nothing. Nevertheless, with respect to all phenomena, that is, all things which can come within our experience, time is necessarily objective. We cannot say that all things are in time, because, if we speak of things in general, nothing is said about the manner of intuition, which is the real condition under which time enters into our representation of things. If therefore this condition is added to the concept, and if we say that all things as phenomena (as objects of sensuous intuition) are in time, then such a proposition has its full objective validity and a priori universality.

What we insist on therefore is the empirical reality of time, that is, its objective validity, with reference to all objects which can ever come before our senses. And as our intuition must at all times be sensuous, no object can ever fall under our experience that does not come under the conditions of time. What we deny is, that time has any claim on absolute reality, so that, without [p. 36] taking into account the form of our sensuous condition, it should by itself be a condition or quality inherent in things; for such qualities which belong to things by themselves can never be given to us through the senses. This is what constitutes the transcendental ideality of time, so that, if we take no account of the subjective conditions of our sensuous intuitions, time is nothing, and cannot be added to the objects by themselves (without their relation to our intuition) whether as subsisting or inherent. This ideality of time, however, as well as that of space, should not be confounded with the deceptions of our sensations, because in their case we always suppose that the phenomenon to which such predicates belong has objective reality, which is not at all the case here, except so far as this objective reality is purely empirical, that is, so far as the object itself is looked upon as a mere phenomenon. On this subject see a previous note, in section i, on Space.

Explanation

Against this theory which claims empirical, but denies absolute and transcendental reality to time, even intelligent men have protested so unanimously, that I suppose that every reader who is unaccustomed to these considerations may naturally be of the same opinion. What they object to is this: Changes, they say, are real (this is proved by the change of our own representations, even [p. 37] if all external phenomena and their changes be denied). Changes, however, are possible in time only, and therefore time must be something real. The answer is easy enough. I grant the whole argument. Time certainly is something real, namely, the real form of our internal intuition. Time therefore has subjective reality with regard to internal experience: that is, I really have the representation of time and of my determinations in it. Time therefore is to be considered as real, not so far as it is an object, but so far as it is the representation of myself as an object. If either I myself or any other being could see me without this condition of sensibility, then these self-same determinations which we now represent to ourselves as changes, would give us a kind of knowledge in which the representation of time, and therefore of change also, would have no place. There remains therefore the empirical reality of time only, as the condition of all our experience, while absolute reality cannot, according to what has just been shown, be conceded to it. Time is nothing but the form of our own internal intuition.1 Take away the peculiar condition of our sensibility, and the idea of time vanishes, because it is not inherent in the objects, but in the subject only that perceives them. [p. 38]

The reason why this objection is raised so unanimously, and even by those who have nothing very tangible to say against the doctrine of the ideality of space, is this. They could never hope to prove apodictically the absolute reality of space, because they are confronted by idealism, which has shown that the reality of external objects does not admit of strict proof, while the reality of the object of our internal perceptions (the perception of my own self and of my own status) is clear immediately through our consciousness. The former might be merely phenomenal, but the latter, according to their opinion, is undeniably something real. They did not see that both, without denying to them their reality as representations, belong nevertheless to the phenomenon only, which must always have two sides, the one when the object is considered by itself (without regard to the manner in which it is perceived, its quality therefore remaining always problematical), the other, when the form of the perception of the object is taken into consideration; this form belonging not to the object in itself, but to the subject which perceives it, though nevertheless belonging really and necessarily to the object as a phenomenon.

Time and space are therefore two sources of knowledge from which various a priori synthetical cognitions [p. 39] can be derived. Of this pure mathematics give a splendid example in the case of our cognitions of space and its various relations. As they are both pure forms of sensuous intuition, they render synthetical propositions a priori possible. But these sources of knowledge a priori (being conditions of our sensibility only) fix their own limits, in that they can refer to objects only in so far as they are considered as phenomena, but cannot represent things as they are by themselves. That is the only field in which they are valid; beyond it they admit of no objective application. This ideality of space and time, however, leaves the truthfulness of our experience quite untouched, because we are equally sure of it, whether these forms are inherent in things by themselves, or by necessity in our intuition of them only. Those, on the contrary, who maintain the absolute reality of space and time, whether as subsisting or only as inherent, must come into conflict with the principles of experience itself. For if they admit space and time as subsisting (which is generally the view of mathematical students of nature) they have to admit two eternal infinite and self-subsisting nonentities (space and time), which exist without their being anything real, only in order to comprehend all that is real. If they take the second view (held by some metaphysical students [p. 40] of nature), and look upon space and time as relations of phenomena, simultaneous or successive, abstracted from experience, though represented confusedly in their abstracted form, they are obliged to deny to mathematical propositions a priori their validity with regard to real things (for instance in space), or at all events their apodictic certainty, which cannot take place a posteriori, while the a priori conceptions of space and time are, according to their opinion, creations of our imagination only. Their source, they hold, must really be looked for in experience, imagination framing out of the relations abstracted from experience something which contains the general character of these relations, but which cannot exist without the restrictions which nature has imposed on them. The former gain so much that they keep at least the sphere of phenomena free for mathematical propositions; but, as soon as the understanding endeavours to transcend that sphere, they become bewildered by these very conditions. The latter have this advantage that they are not bewildered by the representations of space and time when they wish to form judgments of objects, not as phenomena, but only as considered by the understanding; but they can neither account for the possibility of mathematical knowledge a priori (there being, according to them, no true and objectively valid intuition a priori), nor can they bring the laws of experience into true harmony with the a priori doctrines of mathematics. According to our theory of the true character of these original [p. 41] forms of sensibility, both difficulties vanish.

Lastly, that transcendental æsthetic cannot contain more than these two elements, namely, space and time, becomes clear from the fact that all other concepts belonging to the senses, even that of motion, which combines both, presuppose something empirical. Motion presupposes the perception of something moving. In space, however, considered by itself, there is nothing that moves. Hence that which moves must be something which, as in space, can be given by experience only, therefore an empirical datum. On the same ground, transcendental æsthetic cannot count the concept of change among its a priori data, because time itself does not change, but only something which is in time. For this, the perception of something existing and of the succession of its determinations, in other words, experience, is required.

GENERAL OBSERVATIONS ON TRANSCENDENTAL ÆSTHETIC

In order to avoid all misapprehensions it will be necessary, first of all, to declare, as clearly as possible, what is our view with regard to the fundamental nature of [p. 42] sensuous knowledge.

What we meant to say was this, that all our intuition is nothing but the representation of phenomena; that things which we see are not by themselves what we see, nor their relations by themselves such as they appear to us, so that, if we drop our subject or the subjective form of our senses, all qualities, all relations of objects in space and time, nay space and time themselves, would vanish. They cannot, as phenomena, exist by themselves, but in us only. It remains completely unknown to us what objects may be by themselves and apart from the receptivity of our senses. We know nothing but our manner of perceiving them, that manner being peculiar to us, and not necessarily shared in by every being, though, no doubt, by every human being. This is what alone concerns us. Space and time are pure forms of our intuition, while sensation forms its matter. What we can know a priori — before all real intuition, are the forms of space and time, which are therefore called pure intuition, while sensation is that which causes our knowledge to be called a posteriori knowledge, i.e. empirical intuition. Whatever our sensation may be, these forms are necessarily inherent in it, while sensations themselves may be of the most different character. Even if we could impart the [p. 43] highest degree of clearness to our intuition, we should not come one step nearer to the nature of objects by themselves. We should know our mode of intuition, i.e. our sensibility, more completely, but always under the indefeasible conditions of space and time. What the objects are by themselves would never become known to us, even through the clearest knowledge of that which alone is given us, the phenomenon.

It would vitiate the concept of sensibility and phenomena, and render our whole doctrine useless and empty, if we were to accept the view (of Leibniz and Wolf), that our whole sensibility is really but a confused representation of things, simply containing what belongs to them by themselves, though smothered under an accumulation of signs (Merkmal) and partial concepts, which we do not consciously disentangle. The distinction between confused and well-ordered representation is logical only, and does not touch the contents of our knowledge. Thus the concept of Right, as employed by people of common sense, contains neither more nor less than the subtlest speculation can draw out of it, only that in the ordinary practical use of the word we are not always conscious of the manifold ideas contained in that thought. But no one would say therefore that the ordinary concept of Right was sensuous, containing a mere phenomenon; for Right can never become a phenomenon, being a concept of [p. 44] the understanding, and representing a moral quality belonging to actions by themselves. The representation of a Body, on the contrary, contains nothing in intuition that could belong to an object by itself, but is merely the phenomenal appearance of something, and the manner in which we are affected by it. This receptivity of our knowledge is called sensibility. Even if we could see to the very bottom of a phenomenon, it would remain for ever altogether different from the knowledge of the thing by itself.

This shows that the philosophy of Leibniz and Wolf has given a totally wrong direction to all investigations into the nature and origin of our knowledge, by representing the difference between the sensible and the intelligible as logical only. That difference is in truth transcendental. It affects not the form only, as being more or less confused, but the origin and contents of our knowledge; so that by our sensibility we know the nature of things by themselves not confusedly only, but not at all. If we drop our subjective condition, the object, as represented with its qualities bestowed on it by sensuous intuition, is nowhere to be found, and cannot possibly be found; because its form, as phenomenal appearance, is determined by those very subjective conditions.

It has been the custom to distinguish in phenomena [p. 45] that which is essentially inherent in their intuition and is recognised by every human being, from that which belongs to their intuition accidentally only, being valid not for sensibility in general, but only for a particular position and organisation of this or that sense. In that case the former kind of knowledge is said to represent the object by itself, the latter its appearance only. But that distinction is merely empirical. If, as generally happens, people are satisfied with that distinction, without again, as they ought, treating the first empirical intuition as purely phenomenal also, in which nothing can be found belonging to the thing by itself, our transcendental distinction is lost, and we believe that we know things by themselves, though in the world of sense, however far we may carry our investigation, we can never have anything before us but mere phenomena. To give an illustration. People might call the rainbow a mere phenomenal appearance during a sunny shower, but the rain itself the thing by itself. This would be quite right, physically speaking, and taking rain as something which, in our ordinary experience and under all possible relations to our senses, can be determined thus and thus only in our intuition. But if we take the empirical in general, and ask, [p. 46] without caring whether it is the same with every particular observer, whether it represents a thing by itself (not the drops of rain, for these are already, as phenomena, empirical objects), then the question as to the relation between the representation and the object becomes transcendental, and not only the drops are mere phenomena, but even their round shape, nay even the space in which they fall, are nothing by themselves, but only modifications or fundamental dispositions of our sensuous intuition, the transcendental object remaining unknown to us.

The second important point in our transcendental æsthetic is, that it should not only gain favour as a plausible hypothesis, but assume as certain and undoubted a character as can be demanded of any theory which is to serve as an organum. In order to make this certainty self-evident we shall select a case which will make its validity palpable.

Let us suppose that space and time are in themselves objective, and conditions of the possibility of things by themselves. Now there is with regard to both a large number of a priori apodictic and synthetical propositions, and particularly with regard to space, which for this reason we shall chiefly investigate here as an illustration. As the propositions of geometry are known synthetically a priori, and with apodictic certainty, I ask, whence do you take such propositions? and what does the [p. 47] understanding rely on in order to arrive at such absolutely necessary and universally valid truths? There is no other way but by concepts and intuitions, and both as given either a priori or a posteriori. The latter, namely empirical concepts, as well as the empirical intuition on which they are founded, cannot yield any synthetical propositions except such as are themselves also empirical only, that is, empirical propositions, which can never possess that necessity and absolute universality which are characteristic of all geometrical propositions. As to the other and only means of arriving at such knowledge through mere concepts or intuitions a priori, it must be clear that only analytical, but no synthetical knowledge can ever be derived from mere concepts. Take the proposition that two straight lines cannot enclose a space and cannot therefore form a figure, and try to deduce it from the concept of straight lines and the number two; or take the proposition that with three straight lines it is possible to form a figure, and try to deduce that from those concepts. All your labour will be lost, and in the end you will be obliged to have recourse to intuition, as is always done in geometry. You then give yourselves an object in intuition. But of what kind is it? [p. 48] Is it a pure intuition a priori or an empirical one? In the latter case, you would never arrive at a universally valid, still less at an apodictic proposition, because experience can never yield such. You must therefore take the object as given a priori in intuition, and found your synthetical proposition on that. If you did not possess in yourselves the power of a priori intuition, if that subjective condition were not at the same time, as to the form, the general condition a priori under which alone the object of that (external) intuition becomes possible, if, in fact, the object (the triangle) were something by itself without any reference to you as the subject, how could you say that what exists necessarily in your subjective conditions of constructing a triangle, belongs of necessity to the triangle itself? For you could not add something entirely new (the figure) to your concepts of three lines, something which should of necessity belong to the object, as that object is given before your knowledge of it, and not by it. If therefore space, and time also, were not pure forms of your intuition, which contains the a priori conditions under which alone things can become external objects to you, while, without that subjective condition, they are nothing, you could not predicate anything of external objects a priori and synthetically. It is therefore beyond the reach of doubt, and not possible [p. 49] only or probable, that space and time, as the necessary conditions of all experience, external and internal, are purely subjective conditions of our intuition, and that, with reference to them, all things are phenomena only, and not things thus existing by themselves in such or such wise. Hence, so far as their form is concerned, much may be predicated of them a priori, but nothing whatever of the things by themselves on which these phenomena may be grounded.1

[1 ]The Germans are the only people who at present (1781) use the word æsthetic for what others call criticism of taste. There is implied in that name a false hope, first conceived by the excellent analytical philosopher, Baumgarten, of bringing the critical judgment of the beautiful under rational principles, and to raise its rules to the rank of a science. But such endeavours are vain. For such rules or criteria are, according to their principal sources, empirical only, and can never serve as definite a priori rules for our judgment in matters of taste; on the contrary, our judgment is the real test of the truth of such rules. It would be advisable therefore to drop the name in that sense, and to apply it to a doctrine which is a real science, thus approaching more nearly to the language and meaning of the ancients with whom the division into α[Editor: illegible character.]σθητ ὰ καὶ νοητά was very famous (or to share that name in common with speculative philosophy, and thus to use æsthetic sometimes in a transcendental, sometimes in a psychological sense).

[1 ]No. 5 (No. 4) is differently worded in the Second Edition; see Supplement VIII.

[1 ]This passage to ‘my object in what I have said’ is differently worded in the Second Edition; see Supplement IX.

[1 ]In the Second Edition the title is, Metaphysical exposition of the concept of time, with reference to par. 5, Transcendental exposition of the concept of time.

[1 ]I retain the reading of the First Edition, vor derselben, nicht durch dieselbe. Von denselben, the reading of later editions, is wrong; the emendation of Rosenkranz, vor denselben, nicht durch dieselben, unnecessary. The Second Edition has likewise vor derselben.

[1 ]Here follows in the Second Edition, Supplement X.

[2 ]Read allein instead of alle.

[1 ]I can say indeed that my representations follow one another, but this means no more than that we are conscious of them as in a temporal succession, that is, according to the form of our own internal sense. Time, therefore, is nothing by itself, nor is it a determination inherent objectively in things.

[1 ]Here follows in the Second Edition, Supplement XI.