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

by Norman Kemp Smith

Third Proof.[1206]—This is for the most part merely a restatement of the first proof. It differs from it in making rather more explicit that the objective reference involved in the notion of the transcendental object is one that carries the mind beyond all representations to the thought of something which determines their order according to a rule. Otherwise the ambiguities of the terms employed are identical with those of the first proof. Its concluding paragraph, however, is a much clearer statement of the difficult argument of A 192-3 = B 238-9.

Fourth Proof.[1207]—This proof differs from all the others. It argues from the characteristics of pure time to the properties necessary to the empirical representation of the time-series. As time cannot be experienced in and by itself, all its essential characteristics must be capable of being represented in terms of appearance. “Only in appearances can we empirically recognise continuity in the connection of times.” The primary function of the understanding is to make such recognition possible, and it does so by “transferring the time order to the appearances and their existence.” It is a necessary law of time that we can only advance to the succeeding through the preceding. Each moment of time is the indispensable condition of the existence of that which follows it. We can pass to the year 1915 only by way of the preceding year 1914. And since, as just noted, time is not cognisable by itself but only as the form of our perceptions, this law must be applicable to them. We can only be conscious of all times as successively conditioning one another in one single time, and that means in one single objective time, if we are conscious of all the phenomena perceived as conditioning one another in their order in time.

It is somewhat difficult to understand how Kant came to formulate the argument in this form. The explanation may perhaps be found in his preoccupation[1208] with the doctrine of a transcendental activity of the productive imagination and with the connected doctrine of a pure a priori manifold. For this proof would seem to rest upon the assumption that the characteristics of time are known purely a priori and therefore with complete certainty, independently of sense experience. The unusual and somewhat scholastic character of the proof also appears in Kant’s substitution of the principle of sufficient reason for the principle of causality. But despite the artificial character of the standpoint, the argument serves to bring prominently forward Kant’s central thesis, viz. that the principle of causality is presupposed in all consciousness of time, even of the subjectively successive. Also, by emphasising that time in and by itself can never be “an object of perception,” and that the relating of appearances to “absolute time” is possible only through the determining of them in their relations to one another, it supplies the data for correction of its own starting-point.

Fifth Proof.[1209]—This proof is probably later than the preceding proofs. Though its essential content coincides with that of the opening proof, its formulation would seem to be a first attempt at statement of the sixth proof, i.e. of the argument which Kant added in the second edition. Adickes considers this proof to be earlier in date than the first four proofs, but the reason which he assigns for so regarding it, viz. that Kant here postulates a synthesis of the imagination independent of the categories as preceding a synthesis of apprehension in terms of the categories, seems to be based upon a much too literal reading of Kant’s loose mode of statement. The argument rather appears to be, as in the sixth proof, that synthesis of the imagination may be either subjective or objective; and the term “apprehension” would seem to be used as signifying that the manifold synthesised is given to the imagination through actual sense experience, and that as thus given it has a determinate order of its own. The argument concludes with the statement (more definite than any to be found in the preceding arguments), that the proof of the principle of causality consists in its indispensableness as a condition of all empirical judgments, and so of experience as such. As a ground of the possibility of experience it must be valid of all the objects of experience.

Sixth Proof.[1210]—The argument of the fifth proof is here more clearly stated. All synthesis is due to “the faculty of imagination which determines inner sense in respect of the time relation.” Such synthesis may, however, yield the consciousness either of subjective succession or of succession “in the object.” In the latter form it presupposes the employment of a pure concept of the understanding, that of the relation of cause and effect. And the conclusion reached is again that only so is empirical knowledge possible. This mode of stating the argument is far from satisfactory. It tends to obscure Kant’s central thesis, that only through consciousness of an objective order is consciousness of subjective sequence possible, and that the principle of causality is therefore a conditioning factor of all consciousness. The misleading distinction drawn in the Prolegomena between judgments of perception and judgments of experience also crops out in Kant’s use of the phrase “mere perception.”[1211]

We may again return to Kant’s central argument. For we have still to consider certain objections to which it may seem to lie open, and also to comment upon Kant’s further explanations in the remaining paragraphs of the section.[1212] Kant’s imperfect statement of his position has suggested to Hutchison Stirling and others a problem which is largely artificial, namely, how the mind is enabled to recognise the proper occasions upon which to apply the category of causality. On the one hand sequence as such cannot be the criterion, since many sequences are not causal, and on the other hand the absence of sequence does not appear to debar its application, since cause and effect would frequently seem to be co-existent. This difficulty arises from failure to appreciate the central thesis upon which Kant’s proof of the principle of causality ultimately rests. Kant’s diffuse and varying mode of statement may conceal but never conflicts with that thesis, which consists in the contention that the category of causality is a necessary and invariable factor in all consciousness. Nothing can be apprehended save in terms of it.[1213] It prescribes an interpretation which the mind has no option save to apply in the consciousness of each and every event, of the coexistent no less than of the sequent. Whether two changes are coexistent or are successive, each must be conceived as possessing an antecedent cause. The only difference is that in the case of sequent events one of them (i.e. the antecedent change) may, upon empirical investigation, be found to be itself the cause of the second and subsequent event, whereas with coexistent events this can never be possible. As the principle of causality is that every event must have an antecedent cause, it follows that where there is no sequence there can be no causation. But when Kant states that sequence is “the sole empirical criterion”[1214] of the causal relation, he does less than justice to the position he is defending. The empirical criteria are manifold in number, and are such as John Stuart Mill has attempted to formulate in his inductive methods.

Schopenhauer has objected[1215] that Kant’s argument proves too much, since it would involve that all objective sequences, such as that of night and day or of the notes in a piece of music, are themselves causal sequences. This criticism has been replied to by Stadler[1216] in the following terms:

“When Schopenhauer adduces the sequence of musical notes or of day and night, as objective sequences which can be known without the causal law, we need only meet him with the question, Where in these cases is the substance that changes? So soon as he is forced to put his objection into the form required to bring it into relation to the question of the possibility of knowledge, his error becomes obvious. His instances must then be expressed thus:—The instrument passes from one state of sound into another; the earth changes from the measure of enlightenment which makes day, to that which makes night. Of such changes no one will say that they are not referred to a cause. And we may quote in this reference the appropriate saying of Kant himself, ‘Days are, as it were, the children of Time, since the following day with that which it contains is the product of the previous day.’”

Night and day, in so far as they are sequent events, must be conceived in terms of causality, not in the sense that night causes day, but as being determined by causes that account not only for each separately, but also for the alternating sequence of the one upon the other. Such causes are found by the astronomer to lie in the changing positions of the earth relatively to the sun.

Schopenhauer adds a further objection of a more subtle nature, which has again been excellently stated and answered by Stadler: