If time travel is possible, presumably so is my shooting my younger self ; then apparently I can kill him – I can commit retrosuicide. But if I were to kill him I would not exist to shoot him, so how can I kill him? The standard solution to this paradox understands ability as compossibility with the relevant facts and points to an equivocation about which facts are relevant: my killing YS is compossible with his proximity but not with his (...) survival, so I can kill him if facts like his survival are irrelevant but I cannot if they are relevant. I identify a lacuna in this solution, namely its reliance without argument on the hidden assumption that my killing YS is possible: if it is impossible, it is not compossible with anything. I argue that this lacuna is important, and I sketch a different solution to the paradox. (shrink)

Agents are morally responsible for their actions only if they understand what they are doing. This much seems clear, but it is unclear exactly what agents must understand in order to be morally responsible; in other words, the epistemic condition for moral responsibility is difficult to discover. In this paper, I will investigate Aquinas’s discussion of knowledge, voluntariness, and moral responsibility in order to discover his views on this condition. Although he never provides a formal expression of such a condition, (...) I will use his discussions of related issues to construct a three-part epistemic condition for moral responsibility. In the process I will raise and discuss several interpretative difficulties, arguing that while some can be resolved, others, despite recent claims to the contrary, resist resolution. Finally, I will draw out several consequences of his account, noteworthy for a variety of reasons. (shrink)