Nevertheless, the pa.s.sage under consideration may be said to lay bare an important presupposition of self-consciousness. It is true that self-consciousness would be impossible, if we merely apprehended the parts of the world in isolation. To be conscious that I who am perceiving C perceived B and A, I must be conscious at once of A, B, and C, in one act of consciousness or apprehension. To be conscious separately of A and B and C is not to be conscious of A and B and C.

And, to be conscious of A and B and C in one act of consciousness, I must apprehend A, B, and C as related, i. e. as forming parts of a whole or system. Hence it is only because our consciousness of A, B, and C is never the consciousness of a mere A, a mere B, and a mere C, but is always the consciousness of A B C as elements in one world that we can be conscious of our ident.i.ty in apprehending A, B, and C. If _per impossibile_ our apprehension be supposed to cease to be an apprehension of a plurality of objects in relation, self-consciousness must be supposed to cease also. At the same time, it is impossible to argue from the consciousness of our ident.i.ty in apprehending to the consciousness of what is apprehended as a unity, and thence to the existence of that unity. For, apart from the consideration that in fact all thinking presupposes the relatedness or--what is the same thing--the necessary relatedness of objects to one another, and that therefore any a.s.sertion to the contrary is meaningless, the consciousness of objects as a unity is a condition of the consciousness of our ident.i.ty, and therefore any doubt that can be raised in regard to the former can be raised equally with regard to the latter.

We may now pa.s.s to the concluding portion of the deduction. For the purpose of considering it, we may sum up the results of the preceding discussion by saying that Kant establishes the synthesis of the manifold on certain principles by what are really two independent lines of thought. The manifold may be regarded either as something which, in order to enter into knowledge, must be given relation to an object, or as something with respect to which self-consciousness must be possible. Regarded in either way, the manifold, according to Kant, involves a process of synthesis on certain principles, which makes it a systematic unity. Now Kant introduces the categories by maintaining that they are the principles of synthesis in question. "I a.s.sert that the above mentioned _categories_ are nothing but the _conditions of thinking in a possible experience_.... They are fundamental conceptions by which we think objects in general for phenomena."[82]

A synthesis according to the categories is 'that wherein alone apperception can prove _a priori_ its thorough-going and necessary ident.i.ty'.[83] In the first edition this identification is simply a.s.serted, but in the second Kant offers a proof.[84]

[82] A. 111, Mah. 204. Cf. A. 119, Mah. 210.

[83] A. 112, Mah. 204.

[84] Cf. p. 161.

Before, however, we consider the proof, it is necessary to refer to a difficulty which seems to have escaped Kant altogether. The preceding account of the synthesis involved in knowledge and in self-consciousness implies, as his ill.u.s.trations conclusively show, that the synthesis requires a particular principle which const.i.tutes the individual manifold a whole of a particular kind.[85] But, if this be the case, it is clear that the categories, which are merely conceptions of an object in general, and are consequently quite general, cannot possibly be sufficient for the purpose. And since the manifold in itself includes no synthesis and therefore no principle of synthesis, Kant fails to give any account of the source of the particular principles of synthesis required for particular acts of knowledge.[86] This difficulty--which admits of no solution--is concealed from Kant in two ways. In the first place, when he describes what really must be stated as the process by which parts or qualities of an object become related to an object of a particular kind, he thinks that he is describing a process by which representations become related to an object in general.[87] Secondly, he thinks of the understanding as the source of general principles of synthesis, individual syntheses and the particular principles involved being attributed to the imagination; and so, when he comes to consider the part played in knowledge by the understanding, he is apt to ignore the need of particular principles.[88] Hence, Kant's proof that the categories are the principles of synthesis can at best be taken only as a proof that the categories, though not sufficient for the synthesis, are involved in it.

[85] Cf. p. 177, note 2, and p. 185.

[86] Cf. pp. 215-17.

[87] Cf. pp. 181-2.

[88] Cf. p. 217.

The proof runs thus:

"I could never satisfy myself with the definition which logicians give of a judgement in general. It is, according to them, the representation of a relation between two conceptions...."

"But if I examine more closely the relation of given representations[89] in every judgement, and distinguish it, as belonging to the understanding, from their relation according to the laws of the reproductive imagination (which has only subjective validity), I find that a judgement is nothing but the mode of bringing given representations under the _objective_ unity of apperception.

This is what is intended by the term of relation 'is' in judgements, which is meant to distinguish the objective unity of given representations from the subjective. For this term indicates the relation of these representations to the original apperception, and also their _necessary unity_, even though the judgement itself is empirical, and therefore contingent, e. g. 'Bodies are heavy.' By this I do not mean that these representations _necessarily_ belong _to each other_ in empirical perception, but that they belong to each other _by means of the necessary unity_ of apperception in the synthesis of perceptions, that is, according to principles of the objective determination of all our representations, in so far as knowledge can arise from them, these principles being all derived from the principle of the transcendental unity of apperception. In this way alone can there arise from this relation _a judgement_, that is, a relation which is _objectively valid_, and is adequately distinguished from the relation of the very same representations which would be only subjectively valid, e. g. according to laws of a.s.sociation. According to these laws, I could only say, 'If I carry a body, I feel an impression of weight', but not 'It, the body, _is_ heavy'; for this is tantamount to saying, 'These two representations are connected in the object, that is, without distinction as to the condition of the subject, and are not merely connected together in the perception, however often it may be repeated.'"[90]

[89] _Erkenntnisse_ here is clearly used as a synonym for representations. Cf. A. 104, Mah. 199.

[90] B. 140-2, M. 86-8; cf. _Prol._, ---- 18-20.

This ground for the identification of the categories with the principles of synthesis involved in knowledge may be ignored, as on the face of it unsuccessful. For the argument is that since the activity by which the synthesis is affected is that of judgement, the conceptions shown by the _Metaphysical Deduction_ to be involved in judgement must const.i.tute the principles of synthesis. But it is essential to this argument that the present account of judgement and that which forms the basis of the _Metaphysical Deduction_ should be the same; and this is plainly not the case.[91] Judgement is now represented as an act by which we relate the manifold of sense in certain necessary ways as parts of the physical world,[92] whereas in the _Metaphysical_ _Deduction_ it was treated as an act by which we relate conceptions; and Kant now actually says that this latter account is faulty. Hence even if the metaphysical deduction had successfully derived the categories from the account of judgement which it presupposed, the present argument would not justify the identification of the categories so deduced with the principles of synthesis. The fact is that Kant's vindication of the categories is in substance independent of the _Metaphysical Deduction_. Kant's real thought, as opposed to his formal presentation of it, is simply that when we come to consider what are the principles of synthesis involved in the reference of the manifold to an object, we find that they are the categories.[93] The success, then, of this step in Kant's vindication of the categories is independent of that of the metaphysical deduction, and depends solely upon the question whether the principles of synthesis involved in knowledge are in fact the categories.

[91] Cf. Caird, i. 348-9 note.

[92] We may notice in pa.s.sing that this pa.s.sage renders explicit the extreme difficulty of Kant's view that 'the objective unity of apperception' is the unity of the parts of nature or of the physical world. How can the 'very same representations' stand at once in the subjective relation of a.s.sociation and in the objective relation which consists in their being related as parts of nature? There is plainly involved a transition from representation, in the sense of the apprehension of something, to representation, in the sense of something apprehended. It is objects apprehended which are objectively related; it is our apprehensions of objects which are a.s.sociated, cf. pp. 233 and 281-2. Current psychology seems to share Kant's mistake in its doctrine of a.s.sociation of ideas, by treating the elements a.s.sociated, which are really apprehensions of objects, as if they were objects apprehended.

[93] Cf. A. 112, Mah. 204; B. 162, M. 99.

The substance of Kant's vindication of the categories may therefore be epitomized thus: 'We may take either of two starting-points. On the one hand, we may start from the fact that our experience is no mere dream, but an intelligent experience in which we are aware of a world of individual objects. This fact is conceded even by those who, like Hume, deny that we are aware of any necessity of relation between these objects. We may then go on to ask how it comes about that, beginning as we do with a manifold of sense given in succession, we come to apprehend this world of individual objects. If we do so, we find that there is presupposed a synthesis on our part of the manifold upon principles const.i.tuted by the categories.

To deny, therefore, that the manifold is so connected is implicitly to deny that we have an apprehension of objects at all. But the existence of this apprehension is plainly a fact which even Hume did not dispute. On the other hand, we may start with the equally obvious fact that we must be capable of apprehending our own ident.i.ty throughout our apprehension of the manifold of sense, and look for the presupposition of this fact. If we do this, we again find that there is involved a combination of the manifold according to the categories.'

In conclusion, attention may be drawn to two points. In the first place, Kant completes his account by at once emphasizing and explaining the paradoxical character of his conclusion. "Accordingly, the order and conformity to law in the phenomena which we call _nature_ we ourselves introduce, and we could never find it there, if we, or the nature of our mind, had not originally placed it there."[94] "However exaggerated or absurd then it may sound to say that the understanding itself is the source of the laws of nature and consequently of the formal unity of nature, such an a.s.sertion is nevertheless correct and in accordance with the object, i. e. with experience."[95] The explanation of the paradox is found in the fact that objects of nature are phenomena. "But if we reflect that this nature is in itself nothing else than a totality[96] of phenomena and consequently no thing in itself but merely a number of representations of the mind, we shall not be surprised that only in the radical faculty of all our knowledge, viz. transcendental apperception, do we see it in that unity through which alone it can be called object of all possible experience, i. e. nature."[97] "It is no more surprising that the laws of the phenomena in nature must agree with the understanding and with its _a priori_ form, that is, its faculty of connecting the manifold in general, than that the phenomena themselves must agree with the _a priori_ form of our sensuous perception. For laws exist in the phenomena as little as phenomena exist in themselves; on the contrary, laws exist only relatively to the subject in which the phenomena inhere, so far as it has understanding, just as phenomena exist only relatively to the subject, so far as it has senses. To things in themselves their conformity to law would necessarily also belong independently of an understanding which knows them. But phenomena are only representations of things which exist unknown in respect of what they may be in themselves. But, as mere representations, they stand under no law of connexion except that which the connecting faculty prescribes."[98]

[94] A. 125, Mah. 214.

[95] A. 127, Mah. 216.

[96] _Inbegriff._

[97] A. 114, Mah. 206.

[98] B. 164, M. 100.

In the second place, this last paragraph contains the real reason from the point of view of the deduction[99] of the categories for what may be called the negative side of his doctrine, viz. that the categories only apply to objects of experience and not to things in themselves.

According to Kant, we can only say that certain principles of connexion apply to a reality into which we introduce the connexion.

Things in themselves, if connected, are connected in themselves and apart from us. Hence there can be no guarantee that any principles of connexion which we might a.s.sert them to possess are those which they do possess.

[99] The main pa.s.sage (B. 146-9, M. 90-2), in which he argues that the categories do not apply to things in themselves, ignores the account of a conception as a principle of synthesis, upon which the deduction turns, and returns to the earlier account of a conception as something opposed to a perception, i. e. as that by which an object is thought as opposed to a perception by which an object is given.

Consequently, it argues merely that the categories, as conceptions, are empty or without an object, unless an object is given in perception, and that, since things in themselves are not objects of perception, the categories are no more applicable to things in themselves than are any other conceptions.

CHAPTER IX

GENERAL CRITICISM OF THE TRANSCENDENTAL DEDUCTION OF THE CATEGORIES

The preceding account of Kant's vindication of the categories has included much criticism. But the criticism has been as far as possible restricted to details, and has dealt with matters of principle only so far as has been necessary in order to follow Kant's thought. We must now consider the position as a whole, even though this may involve some repet.i.tion.[1] The general difficulties of the position may be divided into two kinds, (1) difficulties involved in the working out of the theory, even if its main principles are not questioned, and (2) difficulties involved in accepting its main principles at all.

[1] Difficulties connected with Kant's view of self-consciousness will be ignored, as having been sufficiently considered.

The initial difficulty of the first kind, which naturally strikes the reader, concerns the possibility of performing the synthesis. The mind has certain general ways of combining the manifold, viz. the categories. But on general grounds we should expect the mind to possess only one mode of combining the manifold. For the character of the manifold to be combined cannot affect the mind's power of combination, and, if the power of the mind consists in combining, the combining should always be of the same kind. Thus, suppose the manifold given to the mind to be combined consisted of musical notes, we could think of the mind's power of combination as exercised in combining the notes by way of succession, _provided that_ this be regarded as the only mode of combination. But if the mind were thought also capable of combining notes by way of simultaneity, we should at once be confronted with the insoluble problem of determining why the one mode of combination was exercised in any given case rather than the other. If, several kinds of synthesis being allowed, this difficulty be avoided by the supposition that, not being incompatible, they are all exercised together, we have the alternative task of explaining how the same manifold can be combined in each of these ways. As a matter of fact, Kant thinks of manifolds of different kinds as combined or related in different ways; thus events are related causally and quant.i.ties quant.i.tatively. But since, on Kant's view, the manifold as given is unrelated and all combination comes from the mind, the mind should not be held capable of combining manifolds of different kinds differently. Otherwise the manifold would in its own nature imply the need of a particular kind of synthesis, and would therefore not be unrelated.

Suppose, however, we waive the difficulty involved in the plurality of the categories. There remains the equally fundamental difficulty that any single principle of synthesis contains in itself no ground for the different ways of its application.[2] Suppose it to be conceded that in the apprehension of definite shapes we combine the manifold in accordance with the conception of figure, and, for the purpose of the argument, that the conception of figure can be treated as equivalent to the category of quant.i.ty. It is plain that we apprehend different shapes, e. g. lines[3] and triangles[4], of which, if we take into account differences of relative length of sides, there is an infinite variety, and houses,[5] which may also have an infinite variety of shape. But there is nothing in the mind's capacity of relating the manifold by way of figure to determine it to combine a given manifold into a figure of one kind rather than into a figure of any other kind; for to combine the manifold into a particular shape, there is needed not merely the thought of a figure in general, but the thought of a definite figure. No 'cue' can be furnished by the manifold itself, for any such cue would involve the conception of a particular figure, and would therefore imply that the particular synthesis was implicit in the manifold itself, in which case it would not be true that all synthesis comes from the mind.

[2] Cf. p. 207.

[3] B. 137, M. 85.

[4] A. 105, Mah. 199.

[5] B. 162, M. 99.

This difficulty takes a somewhat different form in the case of the categories of relation. To take the case of cause and effect, the conception of which, according to Kant, is involved in our apprehension of a succession, Kant's view seems to be that we become aware of two elements of the manifold A B as a succession of events in the world of nature by combining them as necessarily successive in a causal order, in which the state of affairs which precedes B and which contains A contains something upon which B must follow (i. e. a cause of B), which therefore makes it necessary that B must follow A.[6] But if we are to do this, we must in some way succeed in selecting or picking out from among the elements of the manifold that element A which is to be thus combined with B. We therefore need something more than the category. It is not enough that we should think that B has a cause; we must think of something in particular as the cause of B, and we must think of it either as coexistent with, or as identical with, A.

[6] Cf. pp. 291-3.

Kant fails to notice this second difficulty,[7] and up to a certain point avoids it owing to his distinction between the imagination and the understanding. For he thinks of the understanding as the source of general principles of synthesis, viz. the categories, and attributes individual syntheses to the imagination. Hence the individual syntheses, which involve particular principles, are already effected before the understanding comes into play. But to throw the work of effecting individual syntheses upon the imagination is only to evade the difficulty. For in the end, as has been pointed out,[8] the imagination must be the understanding working unreflectively, and, whether this is so or not, some account must be given of the way in which the imagination furnishes the particular principles of synthesis required.

[7] We should have expected Kant to have noticed this difficulty in A. 105, Mah. 199, where he describes what is involved in the relation of representations to an object, for his instance of representations becoming so related is the process of combining elements into a triangle, which plainly requires a synthesis of a very definite kind. For the reasons of his failure to notice the difficulty cf. p. 207.

[8] Pp. 168-9.

The third and last main difficulty of the first kind concerns the relation of the elements of the manifold and the kinds of synthesis by which they are combined. This involves the distinction between relating in general and terms to be related. For to perform a synthesis is in general to relate, and the elements to be combined are the terms to be related.[9] Now it is only necessary to take instances to realize that the possibility of relating terms in certain ways involves two presuppositions, which concern respectively the general and the special nature of the terms to be related.