Is the being in an irreversible persistent vegetative state as the result of a horrible accident numerically identical to the human person, Lindsay, who existed before the accident? Many proponents of Thomistic metaphysics have argued that Aquinas’s answer to this question must be “yes.” In particular, it seems that Aquinas’s commitment to both Aristotelian hylomorphism and the unity of substantial form (viz., that each body/soul composite possesses one and only one substantial form) entails the position that the human person remains (...) alive as long as biological life persists. I argue, however, that although Aquinas does possess a deeply integrated account of human nature and is indeed committed to the claim that the person, Lindsay, exists as long as Lindsay’s body lives, there is good reason to suppose that he also holds that the body in the PVS is not Lindsay’s body in anything more than an equivocal sense. (shrink)

Like Aristotle, Thomas Aquinas holds that the rational soul is the substantial form of the human body. In so doing, he takes himself to be rejecting a Platonic version of substance dualism; his criticisms, however, apply equally to a traditional understanding of Cartesian dualism. Aquinas’s own peculiar brand of dualism is receiving increased attention from contemporary philosophers—especially those attracted to positions that fall between Cartesian substance dualism and reductive materialism. What Aquinas’s own view amounts to, however, is subject to debate. (...) Philosophers (such as J. P. Moreland and Scott Rae) have claimed that ‘Thomistic substance dualism’ (TSD) centers around two beliefs: (1) the rational soul is an immaterial substance, and (2) this immaterial substance is the human person. In this paper, I argue that labeling such an account ‘Thomistic’ proves dangerously misleading—not only does Aquinas himself explicitly deny both of these claims, but he denies them for philosophically significant reasons. Furthermore, I argue that Aquinas’s own position provides an account of human nature both more coherent and philosophically attractive. (shrink)

I investigate Thomas Aquinas's metaphysical account of human death, which is defined in terms of a rational soul separating from its material body. The question at hand concerns what criterion best determines when this separation occurs. Aquinas argues that a body has a rational soul only insofar as it is properly organised to support the soul's vegetative, sensitive, and rational capacities. According to the ‘higher‐brain’ concept of death, when a body can no longer provide the biological foundation necessary for the (...) operation of conscious rational thought and volition, a substantial change occurs in which the rational soul departs and the body left behind is a ‘humanoid animal’ or a mere ‘vegetable.’I argue that the separation of soul and body does not occur until the body ceases to function as a unified, integrated organism. A rational soul is not only the seat of a human being's rational capacities; it is also the principle of the body's sensitive and vegetative capacities. Since Aquinas defines a human being as a composite of soul and body, and not with merely the exercise of rational capacities, the determination of death requires incontrovertible evidence that the body has ceased all the operations that correspond to the soul's proper capacities. The evidence of this is the body's loss of its integrative organic unity and the criterion for determining when this loss occurs is the irreversible cessation of whole‐brain functioning. (shrink)