Yet Kant had also maintained that the ‘I think’ is equivalent to ‘I am,’[1066] and that in this form, as an intellectual consciousness of the self’s existence, it precedes all experience. The teaching of the Postulates is, however, the teaching of the Critique as a whole, and such critics as Pistorius seemed therefore to be justified in maintaining that Kant, in reducing the experiences of inner sense to mere appearance, destroys the possibility of establishing reality in any form. Appearance, in order to be appearance, presupposes the reality not only of that which appears, but also of the mental process whereby it is apprehended. But if reality is given only in sensation, and yet all experience that involves sensation is merely appearance, there is no self by which appearance can be conditioned; and only illusion (Schein), not appearance (Erscheinung), is left. To quote Pistorius’ exact words:
”[If our inner representations are not things in themselves but only appearances] there will be nothing but illusion (Schein), for nothing remains to which anything can appear.”[1067]
Kant evidently felt the force of this criticism, for in the second edition he replies to it on no less than seven different occasions.[1068] In three of these passages[1069] the term Schein is employed, and in the note to B xxxix the term Erdichtung appears. This shows very conclusively that it is such criticism as the above that Kant has in mind. The most explicit passage is B 428:
“The proposition, ‘I think,’ or ‘I exist thinking,’ is an empirical proposition. Such a judgment, however, is conditioned by empirical intuition, and the object that is thought therefore underlies it as appearance. It would consequently seem that on our theory the soul is completely transformed, even in thinking [selbst im Denken], into appearance, and that in this way our consciousness itself, as being a mere illusion [Schein], must refer in fact to nothing.”
Kant, in his reply, is unyielding in the contention that the ‘I think,’ even though it involves an empirical judgment, is itself intellectual. “This representation is a thinking, not an intuiting,”[1070] or as he adds, “The ‘I think’ expresses the actus whereby I determine my existence.” Existence is therefore already given thereby.[1071] Kant also still maintains that the self thus revealed is not “appearance and still less illusion.”
“I am conscious of myself ..., not as I appear to myself, nor as I am in myself, but only that I am.”[1072] “I thereby represent myself to myself neither as I am nor as I appear to myself. I think myself only as I do any object in general from whose mode of intuition I abstract.”[1073]
Kant’s method of meeting the criticism, while still holding to these positions, is twofold. It consists in the first place in maintaining that the ‘I think,’ though intellectual, can find expression only in empirical judgments—in other words, that it is in and by itself formal only, and presupposes as the occasion of its employment a given manifold of inner sense; and secondly, by the statement that the ‘existence’ which is involved in the ‘I think’ is not the category of existence. Let us take in order each of these two points.
Kant’s first method of reply itself appears in two forms, a stronger and a milder. The milder mode of statement[1074] is to the effect that though the representation ‘I am’ already immediately involves the thought of the existence of the subject, it yields no knowledge of it. Knowledge would involve intuition, namely, consciousness of inner determinations in time, which in turn would itself presuppose consciousness of outer objects. As a merely intellectual representation,
“...this ‘I’ has not the least predicate of intuition which, in its character of permanence, could, somewhat after the manner of impenetrability in the empirical intuition of matter, serve as correlate of time determination in inner sense.”[1075]
The stronger and more definite mode of statement is that the ‘I think’ is an empirical proposition.[1076] Though it involves as one factor the intellectual representation, ‘I think,’ it is none the less empirical.