Abstract

Significant scholarship has been devoted to the problem of the incompatibility of Aristotle’s accounts of substance in the Categories and in the Metaphysics. Substance, in the former treatise, is that category of being distinguished from the other accidental categories by reason of the ontological dependence of accident upon substance: every accident must be present in a substance to be present at all. Primary substances such as “Socrates” are distinguished from secondary substances such as “human being” or “animal” since secondary substances are said of primary ones. Only primary substances are neither said of a subject nor present in a subject, depending upon nothing else for their existence. This assertion of the ontological primacy of the individual seems to be withdrawn by Aristotle, however, in the Metaphysics, in which substance emerges in a discussion of the hupokeimenon—the underlying subject of which everything else is predicated. This subject is to be understood in three senses: as matter, as form, and as the composite of the two. Primary substance, finally, is granted to form alone, the “most perplexing” of the candidates, according to Aristotle, and the one that turns out to refer to the same thing as essence. Since what Aristotle means by essence looks to be a form common to all individuals of a particular species, it is not surprising that commentators identify at worst a contradictory theory regarding substance, and at best a transformation of an immature theory of substance into a mature one.