investigating and observing what is present in consciousness; but he was guided by an assumption and pursued a purpose – the purpose of finding what he assumed, in order to add to the Transcendental Æsthetic so happily discovered a Transcendental Logic analogous to it, and thus symmetrically corresponding to it, as a second storey. Now for this purpose he hit upon the table of judgments, out of which he constructed, as well as he could, the table of categories, the doctrine of twelve pure a priori conceptions, which are supposed to be the conditions of our thinking those very things the perception of which is conditioned by the two a priori forms of sensibility: thus a pure understanding now corresponded symmetrically to a pure sensibility. Then another consideration occurred to him, which offered a means of increasing the plausibility of the thing, by the assumption of the schematism of the pure conceptions of the understanding. But just through this the way in which his procedure had, unconsciously indeed, originated betrayed itself most distinctly. For because he aimed at finding something a priori analogous to every empirical function of the faculty of knowledge, he remarked that between our empirical perception and our empirical thinking, conducted in abstract non-perceptible conceptions, a connection very frequently, though not always, takes place, because every now and then we try to go back from abstract thinking to perception; but try to do so merely in order really to convince ourselves that our abstract thought has not strayed far from the safe ground of perception, and perhaps become exaggeration, or, it may be, mere empty talk; much in the same way as, when we are walking in the dark, we stretch out our hand every now and then to the guiding wall. We go back, then, to the perception only tentatively and for the moment, by calling up in imagination a perception corresponding to the conceptions which are occupying us at the time – a perception which can yet never be quite adequate to the conception, but is merely a temporary
