Immanuel Kant's Critique of Pure Reason — trans. F. Max Müller

causes : it being quite possible that the cause of the representations, which are ascribed by us, it may be wrongly, to external things, may lie within ourselves. We, however, have proved that external experience is really immediate,^ and that only by means of it, though not the consciousness of our own existence, yet its determination in time, that is, internal experience, becomes possible. No doubt the representation of / am, which expresses the consciousness that can accompany all thought, is that which immediately includes the existence of a subject : but it does not yet include a knowledge of it, and therefore no empirical knowledge, that is, experience. For that we require, besides the thought of something existing, intuition also, and in this case internal intuition in respect to which, that is, to time, the subject must be determined. For that purpose external objects are absolutely necessary, so that internal experience itself is possible, mediately only, and through external experience.

Note 2. — This view is fully confirmed by the empirical use of our faculty of knowledge, as applied to the determination of time. Not only are we unable to perceive any determination of time, except through a change in external relations (motion) with reference to what is permanent in space (for instance, the movement of the sun with respect to terrestrial objects), but we really have nothing permanent to which we could refer the concept of a substance, as an intuition, except matter only : and even its permanence is not derived from external experience, but

1 The immediate consciousness of the existence of external things is not simply assumed* in the preceding theorem, but proved, whether we can understand the possibility of this consciousness or not. The question with regard to that possibility would come to this, whether we have an internal sense only, and no external sense, but merely an external imagination. It is clear, however, that, even in order to imagine only something as external, that is, to represent it to the senses in intuition, we must have an external sense, and thus distinguish immediately the mere receptivity of an external intuition from that spontaneity which characterizes every act of imagination. For merely to imagine an external sense would really be to destroy the faculty of intuition, which is to be determined by the faculty of imagination.

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presupposed a priori as a necessary condition of all determination of time, and therefore also of ^ the determination of the internal sense with respect to our own existence through the existence of external things. The consciousness of myself, in the representation of the ego, is not an intuition, but a merely intellectual representation of the spontaneity of a thinking subject. Hence that ego has not the slightest predicate derived from intuition, which predicate, as permanent, might serve as the correlate of the determination of time in the internal sense : such as is, for instance, impermeability in matter, as an empirical intuition.

Note 3. — Because the existence of external objects is required for the possibility of a definite consciousness of ourselves, it does not follow that every intuitional representation of external things involves, at the same time, their existence ; for such a representation may well be the mere effect of the faculty of imagination (in dreams as well as in madness); but it can be such an effect only through the reproduction of former external perceptions, which, as we have shown, is impossible without the reality of external objects. What we wanted to prove here was only that internal experience in general is possible only through external experience in general. Whether this or that supposed experience be purely imaginary, must be settled according to its own particular determinations, and through a comparison with the criteria of all real experience.

^ Read der instead of ah.

SUPPLEMENT XXII

[See vol. ii. p. 204]

General Note on the Systetn of the Principles

It is something very remarkable that we cannot understand the possibiHty of anything from the category alone, but must always have an intuition in order to exhibit by it the objective reality of the pure concept of the understanding. Let us take, for instance, the categories of relation. It is impossible to understand, from mere concepts alone : —

First, how something can exist as subject only, and not as a mere determination of other things, that is, how it can be a substance : or,

Secondly, how, because something is, something else must be, that is, how something can ever be a cause : or.