Aristotle's theory of substance in "Metaphysics Zeta-Eta"
The central question in Aristotle' Metaphysics Zeta - Eta is "What is substance?" and Aristotle answers that substance is essence or substantial form. But it is not clear what in Zeta -Eta Aristotle is inquiring and what the conclusion implies. In this study I argue that in Zeta -Eta Aristotle advances a new theory of substance: he establishes a new criterion for substance and identifies substantial form as primary substance. The criteria for substance which I take Aristotle to offer are these two. (1) A thing is a substance if and only if its formula of essence is a definition. (2) A thing is a substance if and only if it has no cause other than itself. The former criterion is derived from a consideration of essence and substance from the formulaic point of view, while the latter is derived from a consideration of essence and substance from the metaphysical point of view. However, Aristotle recognizes a problem in the logical or formulaic criterion. The difficulty is that the definition of substantial form doesn't seem to be different from the definition of a concrete particular in the composite structure of the formula. The definitions of substantial form and a concrete particular are all composed of parts. I claim that such dissatisfaction with the logical criterion is the main reason why Aristotle declares a new beginning in Zeta 17. In Zeta 17 Aristotle claims that it is impossible to identify the cause of the being of substantial form in the same way as the cause of the being of a concrete particular, since the thing asked about is ontologically simple. The cause of the being of a simple thing is itself. Aristotle claims that substantial form, which is the cause of the being of a concrete particular, does not have any cause other than itself. Substantial form is, therefore, primary substance on the metaphysical criterion. This interpretation implies that a concrete particular is not to be ranked as primary substance and that this revision can be taken as "a return to, or a renewal of sympathy with, Plato" as G. E. L. Owen described.
Kim, Hye-Kyung, "Aristotle's theory of substance in "Metaphysics Zeta-Eta"" (1999). Dissertations (1962 - 2010) Access via Proquest Digital Dissertations. AAI9953490.