Proceedings of the American Catholic Philosophical Association

Volume 93, 2019

Elliot Polsky
Pages 263-292

“In As Many Ways As Something Is Predicated . . . in That Many Ways Is Something Signified to Be”
The Logic behind Thomas Aquinas’s Predication Thesis, Esse Substantiale, and Esse in Rerum Natura

Thomistic commentators agree that Thomas Aquinas at least nominally allows for “to be” (esse) to signify not only an act contrasted with essence in creatures, but also the essence itself of those creatures. Nevertheless, it is almost unheard of for any author to interpret Thomas’s use of the word “esse” as referring to essence. Against this tendency, this paper argues that Thomas’s In V Metaphysics argument that every predication signifies esse provides an important instance of Thomas using “esse” to signify essence. This reading of In V Metaphysics, which this paper defends against Gyula Klima’s alternative interpretation, suggests significant reinterpretations of Thomas’s technical terms “esse substantiale” and “esse in rerum natura” as well as Thomas’s use of “is,” both as a copula and as a principal predicate.