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

by Norman Kemp Smith

As the words which I have italicised show, Kant, even in the very sentence in which he asserts outer representations to be inner states, none the less recognises that appearances in space are not representations in the same meaning of that term as are subjective states. They are the objects of representation, not representation itself. The latter alone is correctly describable as a state of the mind. The former may be conditioned by representation, and may therefore be describable as appearances, but are not for that reason to be equated with representation. But before the grounds and nature of this distinction can be formulated in the proper Critical terms, we must consider the reasons which induced Kant to commit himself to this obscure and difficult doctrine of inner sense. As I shall try to show, it is no mere excrescence upon his system; on the contrary, it is inseparably bound up with all his main tenets.

One of the chief influences which constrained Kant to develop this doctrine is the conclusion, so essential to his position, that knowledge must always involve an intuitional manifold in addition to a priori forms and concepts. That being so, he was bound to deny to the mind all power of gaining knowledge by mere reflection. If our mental activities and states lay open to direct inspection, we should have to recognise in the mind a non-sensuous intuitional power. Through self-consciousness or reflection we should acquire knowledge independently of sense. Such apprehension, though limited to the mind’s own operations and states, would none the less be knowledge, and yet would not conform to the conditions which, as the transcendental deduction has shown, are involved in all knowledge. In Kant’s view the belief that we possess self-consciousness of this type, a power of reflection thus conceived, is wholly illusory. To assume any such faculty would be to endow the mind with occult or mystical powers, and would throw us back upon the Leibnizian rationalism, which traces to such reflection our consciousness of the categories, and which rears upon this foundation the entire body of metaphysical science.[990]

The complementary negative conclusion of the transcendental deduction is a no less fundamental and constraining influence in compelling Kant to develop a doctrine of inner sense. If all knowledge is knowledge of appearances, or if, as he states his position in the Analytic of Principles,[991] our knowledge can extend no further than sense experience and inference from such experience, either knowledge of our inner states must be mediated, like our knowledge of outer objects, by sensation, or we can have no knowledge of them whatsoever. On Critical principles, consistently applied, there can be no middle course between acceptance of an indirect empirical knowledge of the mind and assertion of its unknowableness. Mental activities may perhaps be thought in terms of the pure forms of understanding, but in that case their conception will remain as purely problematic and as indeterminate as the conception of the thing in itself. It is impossible for Kant to admit immediate consciousness of the mind’s real activities and states, and at the same time to deny that we can have knowledge of things in themselves. The Aesthetic, in proving that everything in space and time is appearance, implicitly assumes the impossibility of direct self-conscious reflection; and the transcendental deduction in showing that all knowledge involves as correlative factors both sense and thought, has reinforced this conclusion, and calls for its more explicit recognition, in reference to the more inward aspect of experience.

As we have already noted,[992] Kant’s doctrine of inner sense was probably adopted in the early ’seventies, and though it is not itself definitely formulated in the first edition, the chief consequence that follows from it is clearly recognised. Thus in the Aesthetic Kant draws the conclusion that, as time is the form of inner sense, everything apprehended in time, and consequently all inner states and activities, can be known only as appearances. The mind (meaning thereby the ultimate conditioning grounds of consciousness) is as indirectly known as is any other mode of noumenal existence. In the Analytic, whenever he is called upon to express himself upon this and kindred points, he continues to hold to this position; and in the section on the Paralogisms all the main consequences that follow from its acceptance are drawn in the most explicit and unambiguous manner. It is argued that as the inner world, the feelings, volitions and representations of which we are conscious, is a world constructed out of a given manifold yielded by inner sense, and is therefore known only as the appearance of a deeper reality which we have no power of apprehending, it possesses no superiority either of certainty or of immediacy over the outer world of objects in space. We have immediate consciousness of both alike, but in both cases this immediate consciousness rests upon the transcendental synthetic processes whereby such consciousness is conditioned and generated. The transcendental activities fall outside the field of empirical consciousness and therefore of knowledge.

Thus Kant would seem to be maintaining that the radical error committed by the subjective idealists, and with which all the main defects of their teaching are inseparably bound up, lies in their ascription to the mind of a power of direct self-conscious reflection, and consequently in their confusion of the transcendental activities which condition consciousness with the inner states and processes which such consciousness reveals. This has led them to ascribe priority and independence to our inner states, and to regard outer objects as known only by an inference from them. The Critical teaching insists on the distinction between appearance and reality, applies it to the inner life, and so restores to our consciousness of the outer world the certainty and immediacy of which subjective idealism would profess to deprive it. Such are the important conclusions at which Kant arrives in his various “refutations of idealism”; and it will be advisable to consider these refutations in full detail before attempting to complete our statement of his doctrine of inner sense.

KANT’S REFUTATIONS OF IDEALISM

Kant has in a number of different passages attempted to define his Critical standpoint in its distinction from the positions of Descartes and Berkeley. Consideration of these will enable us to follow Kant in his gradual recognition of the manifold consequences to which he is committed by his substitution of inner sense for direct self-conscious intuition or reflection, or rather of the various congenial tenets which it gives him the right consistently to defend and maintain. In Kant’s Critical writings we find no less than seven different statements of his refutation of idealism: (I.) in the fourth Paralogism of the first edition of the Critique; (II.) in section 13 (Anm. ii. and iii.) of the Prolegomena; (III.) in section 49 of the Prolegomena; (IV.) in the second appendix to the Prolegomena; (V.) in sections added in the second edition at the conclusion of the Aesthetic (B 69 ff.); (VI.) in the “refutation of idealism” (B 274-8), in the supplementary section at the end of the section on the Postulates (B 291-4), and in the note to the new preface (B xxxix-xl); (VII.) in the “refutation of problematic idealism” given in the Seven Small Papers which originated in Kant’s conversations with Kiesewetter. Consideration of these in the above order will reveal Kant’s gradual and somewhat vacillating recognition of the new and revolutionary position which alone genuinely harmonises with Critical principles. But first we must briefly consider the various meanings which Kant at different periods assigned to the term idealism. Even in the Critique itself it is employed in a great variety of diverse connotations.

In the pre-Critical writings[993] the term idealism is usually employed in what was its currently accepted meaning, namely, as signifying any philosophy which denied the existence of an independent world corresponding to our subjective representations. But even as thus used the term is ambiguous.[994] It may signify either denial of a corporeal world independent of our representations or denial of an immaterial world “corresponding to” the represented material world, i.e. the denial of Dinge an sich. For there are traceable in Leibniz’s writings two very different views as to the reality of the material world. Sometimes the monads are viewed as purely intelligible substances without materiality of any kind. The kingdom of the extended is set into the representing subjects; only the immaterial world of unextended purely spiritual monads remains as independently real. At other times the monads, though in themselves immaterial, are viewed as constituting through their coexistence an independent material world and a materially occupied space. Every monad has a spatial sphere of activity. The material world is an objective existence due to external relations between the monads, not a merely subjective existence internal to each of them. This alternation of standpoints enabled Leibniz’s successors to deny that they were idealists; and as the more daring and speculative aspects of Leibniz’s teaching were slurred over in the process of its popularisation, it was the second, less consistent view, which gained the upper hand. Wolff, especially in his later writings, denounces idealism; and in the current manuals, sections in refutation of idealism became part of the recognised philosophical teaching. Idealism still, however, continued to be used ambiguously, as signifying indifferently either denial of material bodies or denial of things in themselves. This is the dual meaning which the term presents in Kant’s pre-Critical writings. In his Dilucidatio (1755)[995] he refutes idealism by means of the principle that a substance cannot undergo changes unless it is a substance independent of other substances. Obviously this argument can at most prove the existence of an independent world, not that it is spatial or material. And as Vaihinger adds, it does not even rule out the possibility that changes find their source in a Divine Being. In the Dreams of a Visionseer (1766)[996] Swedenborg is described as an idealist, but without further specification of the exact sense in which the term is employed. In the inaugural Dissertation (1770)[997] idealism is again rejected, on the ground that sense-affection points to the presence of an intelligible object or noumenon.

In Kant’s class lectures on metaphysics,[998] which fall, in part at least, between 1770 and 1781, the term idealism is employed in a very different sense, which anticipates its use in the Appendix to the Prolegomena.[999] The teaching of the Dissertation, that things in themselves are knowable, is now described as dogmatic, Platonic, mystical (schwärmerischer) idealism. He still rejects the idealism of Berkeley, and still entitles it simply idealism, without limiting or descriptive predicates. But now also he employs the phrase “problematic idealism” as descriptive of his own new position. This is, of course, contrary to his invariable usage elsewhere, but is interesting as showing that about this time his repugnance to the term idealism begins to give way, and that he is willing to recognise that the relation of the Critical teaching to idealism is not one of simple opposition. He now begins to regard idealism as a factor, though a radically transformed factor, in his own philosophy.

Study of the Critique reinforces this conclusion. In the Aesthetic Kant teaches the “transcendental ideality” of space and time; and in the Dialectic (in the fourth Paralogism) describes his position as idealism, though with the qualifying predicate transcendental.[1000] But though this involves an extension of the previous connotation of the term idealism, and might therefore have been expected to increase the existing confusion, it has the fortunate effect of constraining Kant to recognise and discriminate the various meanings in which it may be employed. This is done somewhat clumsily, as if it were a kind of afterthought. In the introductory syllogism of the fourth Paralogism Descartes’ position and his own are referred to simply as idealism and dualism respectively. The various possible sub-species of idealism as presented in the two editions of the Critique and in the Prolegomena may be tabulated as follows: