Search

Since the Second World War there has been a revival of interest in the nature of moral evil among professional philosophers. Some have argued that evil is not a profitable moral category, lacking explanatory power, and ought to be abandoned. Other philosophers argue that the concept of evil has a legitimate place in moral philosophy and cannot be abandoned without cost. They argue that there seems to be something conveyed by describing an act as 'evil' in modern contexts which is not captured by calling an act very, very wrong. One thinker who has been largely absent from these discussions is Thomas Aquinas. Part of the reason for this is that Aquinas' account of evil (by which he means badness in a general sense) as a privation of goodness is often assumed to deflate the concept of evil in question. In this thesis, I ask what a Thomistic understanding of moral evil in the relevant sense could look like, and I argue that Aquinas' philosophical writings provide a plausible framework within which the concept can be understood. Specifically, I argue that evil acts in the relevant sense can be understood as those acts by which humans set themselves against the goods which necessarily bind human societies together, and hence decisively alienate the evildoer from any flourishing society. I draw from Aquinas' writings on the nature of moral vice, on capital punishment, and on the 'stain on the soul' left by serious wrongdoing to understand the ways in which people can become evil and the effects that evil actions have on their perpetrators' moral character. Although I in no way shy away from Aquinas' theological writings, the essence of the account as it emerges could be accepted by a secular audience as readily as a religious one. In order to develop this account, it is necessary to explore various aspects of Aquinas’ thought. Firstly, I examine Aquinas’ understanding of love. Love is central to Aquinas’ moral psychology. The entirety of his approach to ethical thought could be summarised as learning how to love well. This includes a discussion of the nature of friendship, and how it is that shared goods unite people as friends. This leads into a discussion of the nature of virtue. Aquinas takes charity, understood as a participation in divine love, as being the form of all virtue. Following this is a discussion of the nature of moral vices, understood as characteristic ways we fail to love well and dispose ourselves to continue in such failures. Then comes a discussion of the metaphysics of evil, understood as a privation of a good that ought to be present but is not. From this comes a discussion and defence of the Guise of the Good principle, which holds that every human action is done for the sake of a real or perceived good. I argue that the principle is entailed by Aquinas’ metaphysics and that it makes sense of apparent counterexamples of people seeking evil for evil’s sake. This leads into a discussion of the nature of evil actions, understood within the context of Aquinas’ overall analysis of human action. Included is an examination of cooperation with evil, and to what extent unwilling participants can become evildoers themselves. I then bring together these different areas of thought into the cohesive theory outlined above, and argue that it well explains common intuitions philosophers have regarding evil.

There has been a recent revival of philosophical interest in the nature of evil. Some philosophers have argued that evil is not a useful moral concept and ought be retired. Other philosophers think that evil is a category with a legitimate place in moral philosophy, and cannot simply be eliminated without cost. These thinkers have come up with various understandings of what evil is and what talk of evil is good for. In this thesis, I elucidate and defend the theory of evil of the medieval philosopher, Thomas Aquinas. This project has two main parts. In the first, I discuss Aquinas’ belief that evil is to be understood as the privation of goodness. I argue that a main weakness of recent defenses of the privation theory of evil stems from a neglect of the intricate metaphysical framework in which Aquinas embedded his moral philosophy. I argue that the theory is plausible when interpreted in this context. In the second part, I examine the Guise of the Good thesis, which holds that every action is done for the sake of some real or perceived good. I argue that this thesis, which is significant to Aquinas’ understanding of evil, also escapes common objections and is plausible when understood in the context of Aquinas’ metaphysics.