earlier Grecian philosophers, never in any one known instance turned to a profitable account. Why, then, being aware that even in idea they were false, besides being practically unsuitable, did Kant adopt or borrow a name laden with this superfetation of reproach--all that is false in theory superadded to all that is useless in practice? He did so for a remarkable reason: he felt, according to his own explanation, that Aristotle had been _groping_ (the German word expressive of his blind procedure is _herumtappen_)--groping in the dark, but under a semi-conscious instinct of truth. Here is a most remarkable case or situation of the human intellect, happening alike to individuals and to entire generations--in the situation of yearning or craving, as it were, for a great idea as yet unknown, but dimly and uneasily prefigured. [19] De Quincey was so fastidious in the matter of grammatical correctness that he would have been shocked to find that he had let this sentence go forth in print.--M. Sometimes the very brink, as it may be called, of such an idea is approached; sometimes it is even imperfectly discovered; but with marks in the very midst of its imperfections which serve as indications to a person coming better armed for ascertaining the sub-conscious thought which had governed their tentative motions. As it stands in Aristotle's scheme, the idea of a category is a mere lifeless abstraction. Rising through a succession of species to genera, and from these to still higher genera, you arrive finally at a highest genus--a naked abstraction, beyond which no farther regress is possible. This highest genus, this _genus generalissimum_, is, in peripatetic language, a category; and no purpose or use has ever been assigned to any one of these categories, of which ten were enumerated at first, beyond that of classification--_i.e._ a purpose of mere convenience. Even for as trivial a purpose as this, it gave room for suspecting a failure, when it was afterwards found that the original ten categories did not exhaust the possibilities of the case; that other supplementary categories (_post-proedicamenta_) became necessary. And, perhaps, "more last words" might even yet be added, supplementary supplements, and so forth, by a hair-splitting intellect. Failures as gross as these, revisals still open to revision, and amendments calling for amendments, were at once a broad confession that here there was no falling in with any great law of nature. The paths of nature may sometimes be arrived at in a tentative way; but they are broad and determinate; and, when found, vindicate themselves. Still, in all this erroneous subtilisation, and these abortive efforts, Kant perceived a grasping at some real idea--fugitive indeed and coy, which had for the present absolutely escaped; but he caught glimpses of it continually in the rear; he felt its necessity to any account of the human understanding that could be satisfactory to one who had meditated on