For of Particulars there is no scientific knowledge, seeing they are infinite. But it is the property of science to rest on general and defined principles. Whence also Particulars are resolved into Universals. And philosophic research is occupied with Conceptions and Real subjects. But since of these the Particulars are infinite, some elements have been found, under which every subject of investigation is brought; and if it be shown to enter into any one or more of the elements, we prove it to exist; but if it escape them all, that it does not exist.
Of things stated, some are stated without connection; as, for example, "man" and "runs," and whatever does not complete a sentence, which is either true or false. And of things stated in connection, some point out "essence," some "quality," some "quantity," some "relation,'' some "where," some "when," some "position," some "possession," some "action," some "suffering," which we call the elements of material things after the first principles. For these are capable of being contemplated by reason.
But immaterial things are capable of being apprehended by the mind alone, by primary application.
Stromateis, Book VIII, Chapter VIII. So the idea seems to be that the categories are the most general heads to which particulars are traced in order to have knowledge of material things; and Clement's position seems to be that terms fall under categories insofar as the terms are used in propositions. The latter makes sense of the fact that Clement immediately goes on to talk about univocal and equivocal terms as things pertaining to what falls under the categories.
