Abstract

In the past years, the relevance of Thomas Aquinas's theory of cognition for contemporary debates on epistemology has been widely discussed. That theory claims that mind and world are formally identical and that this relationship overcomes various problems associated with scepticism concerning mental representation. The proposal, however, is grounded on the idea that the world can act on the mind through a relation of formal causation. This thesis attempts to develop a Thomistic theory of formal causation which may be suitable for a realist account of mental representation and which may meet the requirements prompted by current discussions. The suggested view is grounded on Aquinas's metaphysics, according to which the world is constituted of substances. The claim that change is possible since substances are hylomorphically constituted is defended. Aquinas's claim that some substances have forms which may act independently of matter is also supported. The paradigmatic examples are human souls, i.e. the forms of human beings, whose higher cognitive capacity, i.e. thinking, can be in principle carried on without the need of any material organ. A Thomistic theory of causation is subsequently proposed. It is argued that hylomorphism explains the distinction among four species of causes. Aquinas's attempt to explain causal relations conditionally is developed along the lines suggested by John Mackie's INUS conditional analysis. Jaegwon Kim's implementation of Mackie's proposal through an object-based metaphysics of events is then adapted to the hylomorphical account of substances. On these grounds, a theory of formal causation can be proposed and applied to Aquinas's theory of mental representation. The ensuing proposal is offered not in the spirit of historical exegesis but as a substantive philosophical account and it is Thomistic only in the broad sense that it is built on Aquinas's metaphysics and is consistent with his claims on causation.