Book Review: Aquinas on Ideas

Abstract

Thomas Aquinas’ thought is generally considered, with justification, to be an application of the philosophy of Aristotle to a Christian intellectual context. Aristotle was not the only intellectual source for Aquinas, however, and this article considers the application of Plato’s Ideas, a notion rejected by Aristotle, to the treatment of the relationship between God, seen as Being Itself (ipsum esse) and determinate created beings. It is suggested that in adapting the Ideas to the Christian context Plato transforms their nature in a radical manner.

In I a, 15 of his Summa Theologiae Thomas Aquinas considers the existence of Ideas, a concept more associated with the thought of Plato than with the Aristotelian approach at the center of Aquinas’ thought. Although the complex topic of this aspect of Aquinas’ thought cannot be fully considered here, a partial determination of (a) the necessity for a theory of Ideas in Aquinas’ system and (b) the nature of Ideas in that system. The focus of this article will be on the passage at 1,15 of the Summa.