If at the foundation of our pure rational cognition of thinking beings there lay more than the mere Cogito—if we could likewise call in aid observations on the play of our thoughts, and the thence derived natural laws of the thinking self, there would arise an empirical psychology which would be a kind of physiology of the internal sense and might possibly be capable of explaining the phenomena of that sense. But it could never be available for discovering those properties which do not belong to possible experience (such as the quality of simplicity), nor could it make any apodeictic enunciation on the nature of thinking beings: it would therefore not be a rational psychology. Now, as the proposition “I think” (in the problematical sense) contains the form of every judgement in general and is the constant accompaniment of all the categories, it is manifest that conclusions are drawn from it only by a transcendental employment of the understanding. This use of the understanding excludes all empirical elements; and we cannot, as has been shown above, have any favourable conception beforehand of its procedure. We shall therefore follow with a critical eye this proposition through all the predicaments of pure psychology; but we shall, for brevity’s sake, allow this examination to proceed in an uninterrupted connection. Before entering on this task, however, the following general remark may help to quicken our attention to this mode of argument. It is not merely through my thinking that I cognize an object, but only through my determining a given intuition in relation to the unity of consciousness in which all thinking consists. It follows that I cognize myself, not through my being conscious of myself as thinking, but only when I am conscious of the intuition of myself as determined in relation to the function of thought. All the modi of self-consciousness in thought are hence not conceptions of objects (conceptions of the understanding—categories); they are mere logical functions, which do not present to thought an object to be cognized, and cannot therefore present my Self as an object. Not the consciousness of the determining, but only that of the determinable self, that is, of my internal intuition (in so far as the manifold contained in it can be connected conformably with the general condition of the unity of apperception in thought), is the object.