The Mind–Body Problem for Thomas Aquinas and for Thomists

Abstract

Aquinas’ hylomorphism faces a mind–body problem, similar to that faced by Cartesianism. This claim runs contrary to virtually all contemporary Thomism, according to which Aquinas’ view on the relation between soul and body completely sidesteps any mind–body problem, by having a conceptual frame that is non-mechanistic and non-Cartesian, and by emphasizing the oneness of the human being. Typically, these arguments for Thomas’ hylomorphism omit his view that the human soul is not only the substantial form of the body, but also an efficient cause of bodily motion. In this dissertation, I argue that the human soul’s role as efficient cause is integral to Aquinas’ philosophy of nature and his ethics, so that it should not be omitted by Thomists, and that it cannot be denied without undermining Thomism fatally. Because Thomism must treat the human soul as an efficient cause, it does face a mind–body problem, however. Aquinas, I argue, was aware that his psychology raises such a difficulty, and provides some possible solutions to it, grounded on his doctrine of instrumental causality.