Paul Symington

Powerful Logic: Aquinas's Unified Theory of Prime Matter as Principle of Individuation & Pure Potency


A lean hylomorphism stands as a metaphysical holy grail. A cumbersome feature of traditional hylomorphic ontologies involves the role of prime matter. Prime matter is both so basic that it cannot be examined (in principle) and its engagement with the other hylomorphic elements is far from coherent. One particular problem posed by prime matter is how it is to be understood both as a principle of individuation for material substances and as pure potency. In the talk I shall present Thomas Aquinas’s way of squeezing some intelligibility out of prime matter by modeling it on the idea of logical genus. Such a modeling provides insight into understanding prime matter as substratum, as maximally indeterminate, and as ontologically vague. One of the unusual but exciting things that fall out from this analysis of prime matter by way of logical genus is the Entirety Thesis: “For any substance x, if x has prime matter then the prime matter of x is the same* as x,” where ‘same*’ is understood as “indeterminately identical.” In the talk I shall explore this thesis, addressing the possible criticisms which we can call “The Problem of Substance Monism,”: due to the transitivity of identity it would seem to imply that all substances are identical.

**Click here to listen to the talk**