アリストテレスにおける個別と普遍 : 『形而上学』M巻一〇章の問題を中心として

Abstract

In Metaphysics M 10 Aristotle, supposing substances to be separate in the fashion of individual existing things, has formulated the problem concerning the elements or principles of substances, (a) If these elements are individual and not universal, then (i) nothing besides the elements will exist, since individuals are taken to be unique, that is, one in number and not the same in kind (form) as anything else, and (ii) they will not be knowable, for knowledge is of universals. (b) But if the principles are universal, the substances composed of them will be universal (which contradicts the notion of substances already laid down). According to Aristotle the difficulties lie in accepting the Platonist premise that over and above substances which have the same form there is a single separate entity, the Platonic Form. Aristotle solves the problem on the assumption that (a) the elements or principles are individual. He himself maintains that individuals are not necessarily unique and that there may be infinitely many similar elements and substances. So he meets difficulty (i). Here Aristotle seems to assert that individual substances can have common forms without there being the Platonic Forms, and that these forms are the principles of substances and are individual. Thus according to him forms as the principles will be not only individual, but also universal because of being common to many. But this is not absurd, if he means to say that it is not in reality but in formula (logos) that the forms are universal, though individual in reality. Next Aristotle meets difficulty (ii) by the assertion that potentiality of knowledge (as a hexis which is potential in relation to energeia, though actual to mere potentiality) is of universals, but actuality is of individuals. But he would agree that individual knowledge is not about matters but about forms which individual entities have.