Abstract
Wedin offers an interpretation of Metaphysics Zeta 13, a very important and difficult chapter, where Aristotle apparently denies that substance is a universal, having, on most accounts, already claimed that form is substance, and that form is a universal. This interpretation of the argument of Z.13, Wedin argues, threatens the possibility of attaining a definition of substance, and places in doubt what has gone before in the treatise. According to Wedin, what Aristotle is concerned with in Z.13 is not the denial that substance is a universal but rather with the denial that anything predicated universally of a c‐substance is the substance‐of the c‐substance, which Wedin calls ‘Weak proscription’. In Wedin's account of Z.13, then, Aristotle is continuing to pursue issues first raised in Z.10–11 that have to do with the relations between form and definition, and form and the universal. Wedin also argues that the dilemma at the conclusion of Z.13, regarding the definability of substance, is resolved in Z.16, with the notion of ‘Dual Complexity’, according to which the parts of a form exist potentially in the form, just as the parts of the c‐substance exist potentially in the c‐substance.