Gavin T. Colvert

This dissertation assesses Thomas Aquinas' response to the problem of whether agents can rationally choose to pursue one course of action when they believe another course is better and open to them. The core of the problem lies in the conceptual connection often made between desirability and normative standards of goodness. Given this connection, it is apparently contradictory to claim that a person can rationally choose to do what he or she desires rather than what he or she thinks best, since 'thinking best' is defined in terms of desirability. Aquinas, however, refuses to accept that such behaviour is simply irrational. I argue that Aquinas has a coherent account of deliberately bad choices, although his position has often been misunderstood both by his near contemporaries in the middle ages and also by more recent scholars. More specifically, some have credited him with the view that there is a necessary and sufficient causal connection between practical judgment and intentional action. Against this interpretation, I maintain Aquinas holds that the relationship between practical judgment and choice is contingent. This contingency allows him to make sense of the obvious asymmetry between what agents sometimes want and what they judge is better. Support for this thesis can be found in three principal areas: Aquinas' account of human action and free will, his discussion of the causality of sin and his concept of conscience. In regard to the first, Aquinas argues that the will is contingently related to reasons for action since, while it necessarily wills its perfect and complete good, no possible object of choice in the present life can constitute that good. In regard to the causes of sin, although Aquinas grants that the will cannot tend to evil without some intellectual failure, he argues that this failure is in fact voluntary and posterior to at least some volition. Furthermore, judgments of conscience provide Aquinas with a formal mechanism to explain how it is possible that agents can, in fact, choose to do what they do not think is best.