A Commentary to Kant's 'Critique of Pure Reason'

by Norman Kemp Smith

We may first state the central argument, deferring treatment of such additional points as arise in connection with Kant’s varying formulations of it in his successive proofs. The second Analogy, though crabbedly, diffusely, and even confusedly stated, is one of the finest and most far-reaching pieces of argument in the whole Critique. It is of special historical importance as being Kant’s answer to Hume’s denial of the validity of the causal principle. Hume had maintained that we can never be conscious of anything but mere succession. Kant in reply seeks to prove that consciousness of succession is only possible through consciousness of a necessity that determines the order of the successive events.

Kant, we must bear in mind, accepts much of Hume’s criticism of the category of causality. The general principle that every event must have an antecedent cause is, Kant recognises, neither intuitively certain nor demonstrable by general reasoning from more ultimate truths. It is not to be accounted for by analytic thought, but like all synthetic judgments a priori can only be proved by reference to the contingent fact of actual experience. Secondly, Kant makes no attempt, either in this Analogy or elsewhere in the Critique, to explain the nature and possibility of causal connection, that is, to show how one event, the cause, is able to give rise to another and different event, the effect. We can never by analysis of an effect discover any reason why it must necessarily be preceded by a cause.[1183] Thirdly, the principle of causality, as deduced by Kant and shown to be necessarily involved in all consciousness of time, is the quite general principle that every event must have some cause in what immediately precedes it. What in each special case the cause may be, can only be empirically discovered; and that any selected event is really the cause can never be absolutely certain. The particular causal laws are discovered from experience, not by means of the general principle but only in accordance with it, and are therefore neither purely empirical nor wholly a priori. As even J. S. Mill teaches, the general principle is assumed in every inference to a causal law, and save by thus assuming the general principle the particular inference to causal connection cannot be proved. But at the same time, since the proof of causal connection depends upon satisfaction of those empirical tests which Mill formulates in his inductive methods, such special causal laws can be gathered only from experience.

The starting-point of Kant’s analysis is our consciousness of an objective order in time. This is for Kant a legitimate starting-point since he has proved in the Transcendental Deduction that only through consciousness of the objective is consciousness of the subjective in any form possible. The independent argument by which it is here supported is merely a particular application of the general principle of that deduction. When we apprehend any very large object, such as a house, though we do so by successively perceiving the different parts of it, we never think of regarding these successive perceptions as representing anything successive in the house. On the other hand, when we apprehend successive events in time, such as the successive positions of a ship sailing down stream, we do regard the succession of our experiences as representing objective succession in what is apprehended. Kant therefore feels justified in taking as fact, that we have the power of distinguishing between subjective and objective succession, i.e. between sequences which are determined by the order of our attentive experience and sequences which are given as such. It is this fact which affords Kant a precise method of formulating the problem of the second Analogy, viz. how consciousness of objective change, as distinguished from subjective succession, is possible?

Schopenhauer, owing to the prominence in his system of the principle of sufficient reason, has commented upon this second Analogy in considerable detail;[1184] and we may here employ one of his chief criticisms to define more precisely the general intention of Kant’s argument. The succession in our experiences of the parts of a house and of the positions of a ship is, Schopenhauer maintains, in both cases of genuinely objective character. In both instances the changes are due to the position of two bodies relatively to one another. In the first example one of these bodies is the body of the observer, or rather one of his bodily organs, namely the eye, and the other is the house, in relation to the parts of which the position of the eye is successively altered. In the second example the ship changes its position relatively to the stream. The motion of the eye from roof to cellar is one event; its motion from cellar to roof is a second event; and both are events of the same nature as the sailing of the ship. Had we the same power of dragging the ship upstream that we have of moving the eye in a direction opposite to that of its first movement, the positions of the ship could be reversed in a manner exactly analogous to our reversal of the perceptions of the house.

This criticism is a typical illustration of Schopenhauer’s entire failure to comprehend the central thesis of Kant’s Critical idealism.[1185] The Analytic, so far as the main argument of its objective deduction is concerned, was to him a closed book; and as this second analogy is little else than a special application of the results of the deduction, he was equally at a loss in its interpretation. Kant was himself, of course, in large part responsible for the misunderstanding. The distinction which would seem to be implied by Kant’s language between sequence that is objective and sequence that is merely subjective is completely inconsistent with Critical principles,[1186] and is as thoroughly misleading as that other distinction which he so frequently employs between the a priori and the merely empirical. Schopenhauer, however, regarded these distinctions as valid, and accordingly applies them in the interpretation of Kant’s method of argument. If inner and outer experience are to be contrasted as two kinds of experience, there is, as Schopenhauer rightly insists, no sufficient ground for regarding changes due to movements of the eye as being subjective and those that are due to movements of a ship as being objective. That is not, however, Kant’s intention in the employment of these illustrations. He uses them only to make clear the fairly obvious fact that while in certain cases the order of our perceptions is subjectively initiated, in other cases we apprehend the subjective order of our experiences as corresponding to, and explicable only through, the objective sequence of events. In holding to this distinction Kant is not concerned to deny that even in the order which is determined by the subject’s purposes or caprice objective factors are likewise involved. The fact that the foundations of a house support its roof, and will therefore determine what it is that we shall apprehend when we turn the eye upwards, does not render the order of our apprehensions any the less subjective in character. But that this order is purely subjective, Kant could never have asserted. His Critical principles definitely commit him to the view that even sensations and desires are integral parts of the unitary system of natural law. Kant, as we shall find, is maintaining that some such distinction between subjective and objective sequence as is illustrated in the above contrasted instances must be present from the very start of our experience—must, indeed, be constitutive of experience as such. Out of a consciousness of the purely subjective the notion of the objective can never arise.[1187] Or otherwise stated, consciousness of a time order, even though subjective, must ultimately involve the application of some non-subjective standard.

“I shall be obliged ... to derive the subjective sequence of apprehension from the objective sequence of appearances, because otherwise the former is entirely undetermined, and does not distinguish any one appearance from any other.”[1188]

We interpret the subjective order in terms of an objective system; consciousness of the latter is the necessary presupposition of all awareness. It is as necessary to the interpretation of what is apprehended through the rotating eyeballs as to the apprehension of a moving ship. So far from refusing to recognise that the subjective order of our experiences is objectively conditioned, Kant is prepared to advance to the further assertion that it is only apprehensible when so conceived.

In the third Analogy Kant proceeds to the connected problem, how we can apprehend the parts of a house as simultaneous notwithstanding the sequent relation of our perceptions of them, and what justification we have for thus interpreting the subjectively sequent experiences as representing objective coexistence. Just as Kant in this second Analogy does not argue that irreversibility is by itself proof of causal relation, but only that the consciousness of such irreversibility demands the employment of the conception of causality, so in the third Analogy he does not attempt to reduce the consciousness of coexistence to the consciousness of reversibility, but to prove that only through the application of the conception of reciprocity can the reversibility be properly interpreted. In each case the category conditions the empirical consciousness; the latter is an apprehension of determinate order only in so far as it presupposes the category. Though Kant’s treatment of the third Analogy has less historical importance, and perhaps less intrinsic interest, than the proof of the second Analogy, it is even more significant of the kind of position which he is endeavouring to establish, and I may therefore forewarn the reader that he must not spare himself the labour of mastering its difficult, and somewhat illusive, argument. The doctrines which it expounds at once reinforce and extend the results of the second Analogy, while the further difficulties which it brings to view, but which it is not itself capable of meeting, indicate that the problems of the Analytic call for reconsideration in the light of certain wider issues first broached in the Dialectic.

We may now return to Kant’s main argument. His problem, as we have found, is how consciousness of objective change, as distinguished from subjective succession, is possible. The problem, being formulated in this particular way, demands, Kant felt, careful definition of what is meant by the term ‘objective,’ upon which so much depends. To apply the illustration above used, the house as apprehended is not a thing in itself but only an appearance to the mind. What, then, do we mean by the house, as distinguished from our subjective representations of it, when that house is nothing but a complex (Inbegriff) of representations?[1189] The question and Kant’s answer to it are stated in subjectivist fashion, in terms of his earlier doctrine of the transcendental object. To contrast an object with the representations through which we apprehend it, is only possible if these representations stand under a rule which renders necessary their combination in some one particular way, and so distinguishes this one particular mode of representation as the only true mode from all others. The origin, therefore, of our distinction between the subjectively successive and the succession which is also objective must be due in the one case to the presence of a rule compelling us to combine the events in some particular successive order, and in the other to the absence of such a rule. Our apprehension of the house, for instance, may proceed in any order, from the roof downwards or vice versa, and as the order may always be reversed there is no compulsion upon the mind to regard the order of its apprehension as representing objective sequence. But since in our apprehension of an event B in time, the apprehension of B follows upon the apprehension of a previous event A, and we cannot reverse the order, the mind is compelled to view the order of succession, in terms of the category of causality, as necessitated, and therefore as objective. The order is a necessary order not in the sense that A must always precede B, that A is the cause of B, but that the order, if we are to apprehend it correctly, must in this particular case be conceived as necessary. The succession, that is, need not be conceived as a causal one, but in order to be conceived as objective succession it must be conceived as rendered necessary by connections that are causal.

Having, in this general fashion, shown the bearing of his previous analysis of objective experience upon the problem in hand, Kant proceeds to develop from it his proof of the special principle of causality. The schema of causality is necessary succession in time, and it is through this, its time aspect, that Kant approaches the principle. It has to do with the special case of change. To be conscious of change we must be conscious of an event, that is, of something as happening at a particular point in time. The change, in other words, requires to be dated, and as we are not conscious of time in general, it must be dated by reference to other events, and obviously in this case in relation to the preceding events, in contrast to which it is apprehended as change. But according to the results of our analysis of what constitutes objective experience, it can be fixed in its position in objective time only if it be conceived as related to the preceding events according to a necessary law; and the law of necessary connection in time is the law of causality. In order, then, that something which has taken place may be apprehended as having occurred, that is, as being an objective change, it must be apprehended as necessarily following upon that which immediately precedes it in time, i.e. as causally necessary.