I call all knowledge transcendental which is occupied not so much with objects, as with our a priori concepts of objects.7 A system of such concepts might be called Transcendental Philosophy. But for the present this is again too great an undertaking. We should have to treat therein completely both of analytical knowledge, and of synthetical knowledge a priori, which is more than we intend to do, being satisfied to carry on the analysis so far only as is indispensably necessary in order to recognize in their whole extent the principles of synthesis a priori, which alone concern us. This investigation which should be called a transcendental critique, but not a systematic doctrine, is all we are occupied with at present. It is not meant to extend our knowledge, but only to rectify it, and to become the test of the value of all a priori knowledge. Such a critique therefore is a preparation for a New Organum, or, if that should not be possible, for a Canon at least, according to which hereafter a complete system of a philosophy of pure reason, whether it serve for an expansion or merely for a limitation of it, may be carried out, both analytically and synthetically. That such a system is possible, nay that it need not be so comprehensive as to prevent the hope of its completion, may be gathered from the fact that it would have to deal, not with the nature of things, which is endless, but with the understanding which judges of the nature of things, and this again so far only as its knowledge a priori is concerned. Whatever the understanding possesses a priori, as it has not to be looked for without, can hardly escape our notice, nor is there any reason to suppose that it will prove too extensive for a complete inventory, and for such a valuation as shall assign to it its true merits or demerits.8
II
Division of Transcendental Philosophy
Transcendental Philosophy is with us an idea (of a science) only, for which the critique of pure reason should trace, according to fixed principles, an architectonic plan, guaranteeing the completeness and certainty of all parts of which the building consists. (It is a system of all principles of pure reason.)9 The reason why we do not call such a critique a transcendental philosophy in itself is simply this, that in order to be a complete system, it ought to contain likewise a complete analysis of the whole of human knowledge a priori. It is true that our critique must produce a complete list of all the fundamental concepts which constitute pure knowledge. But it need not give a detailed analysis of these concepts, nor a complete list of all derivative concepts. Such an analysis would be out of place, because it is not beset with the doubts and difficulties which are inherent in synthesis, and which alone necessitate a critique of pure reason. Nor would it answer our purpose to take the responsibility of the completeness of such an analysis and derivation. This completeness of analysis, however, and of derivation from such a priori concepts as we shall have to deal with presently, may easily be supplied, if only they have first been laid down as perfect principles of synthesis, and nothing is wanting to them in that respect.
All that constitutes transcendental philosophy belongs to the critique of pure reason, nay it is the complete idea of transcendental philosophy, but not yet the whole of that philosophy itself, because it carries the analysis so far only as is requisite for a complete examination of synthetical knowledge a priori.
The most important consideration in the arrangement of such a science is that no concepts should be admitted which contain anything empirical, and that the a priori knowledge shall be perfectly pure. Therefore, although the highest principles of morality and their fundamental concepts are a priori knowledge, they do not belong to transcendental philosophy, because the concepts of pleasure and pain, desire, inclination, free-will, etc., which are all of empirical origin, must here be presupposed. Transcendental philosophy is the wisdom of pure speculative reason. Everything practical, so far as it contains motives, has reference to sentiments, and these belong to empirical sources of knowledge.
If we wish to carry out a proper division of our science systematically, it must contain first a doctrine of the elements, secondly, a doctrine of the method of pure reason. Each of these principal divisions will have its subdivisions, the grounds of which cannot however be explained here. So much only seems necessary for previous information, that there are two stems of human knowledge, which perhaps may spring from a common root, unknown to us, viz. sensibility and the understanding, objects being given by the former and thought by the latter. If our sensibility should contain a priori representations, constituting conditions under which alone objects can be given, it would belong to transcendental philosophy, and the doctrine of this transcendental sense-perception would necessarily form the first part of the doctrine of elements, because the conditions under which alone objects of human knowledge can be given must precede those under which they are thought.
1 The beginning of this Introduction down to 'But what is still more extraordinary,' is left out in the Second Edition. Instead of it Supplement IV.
2 The Second Edition gives here a new heading:—III, Philosophy requires a science to determine the possibility, the principles, and the extent of all cognitions a priori.
3 The Second Edition adds here: 'These inevitable problems of pure reason itself are, God, Freedom, and Immortality. The science which with all its apparatus is really intended for the solution of these problems, is called Metaphysic. Its procedure is at first dogmatic, i.e. unchecked by a previous examination of what reason can and cannot do, before it engages confidently in so arduous an undertaking.'
4 These two paragraphs to 'In synthetical judgments a priori, however,' are left out in the Second Edition, and replaced by Supplement V.
5 This paragraph left out in the Second Edition, and replaced by Supplement VI.
6 If any of the ancients had ever thought of asking this question, this alone would have formed a powerful barrier against all systems of pure reason to the present day, and would have saved many vain attempts undertaken blindly and without a true knowledge of the subject in hand.
7 'As with our manner of knowing objects, so far as this is meant to be possible a priori.' Second Edition.
8 Here follows Supplement VII in Second Edition.
9 Addition in the Second Edition.
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Critique of Pure Reason
I
The Elements Of Transcendentalism
First Part
Transcendental Æsthetic
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 faculty of representation (Vorstellungsfähigkeit), so far as we 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 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 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.
First Section Of The Transcendental Æsthetic
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 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. 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 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.2]
Conclusions from the Foregoing Concepts
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 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 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.
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