Abstract

One natural way to argue for the existence of some subjective constraint on agents’ obligations is to maintain that without that particular constraint, agents will sometimes be obligated to do that which they lack the ability to do. In this paper, I maintain that while such a strategy appears promising, it is fraught with pitfalls. Specifically, I argue that because the truth of an ability ascription depends on an (almost always implicit) characterization of the relevant possibility space, different metaethical accounts take obligation to be constrained by different senses of ability. As a result, what initially looks to be a point of consensus—that ability constrains obligation—turns out to be a point of contention, and arguments with this at the foundation are much more likely to obscure, rather than resolve, metaethical disputes. Despite this, appeals to ability in metaethics aren’t doomed to be fruitless. On the contrary, if we can independently establish a particular sense of ability as the normatively relevant one, then we have good grounds for ruling out metaethical accounts that are inconsistent with it. In the final section, I make just such an argument. What seems right about the thought that ability constrains obligation is that an agent cannot be obligated to do that which her circumstances prevent her from doing. I argue that only a sense of ability that is both epistemically and motivationally restricted adequately respects the limits of agential control.