It is commonly held that “ought implies can.” If so, what constraints does that place on the law? Having provided an argument which allows the maxim to be used by lawyers, I consider the application of that argument to both primary and remedial legal duties. This, it turns out, gives us some reason to reconsider whether the maxim is sound. Further, even if the maxim is sound, it has less purchase on remedial duties than is commonly supposed.

I defend the following version of the ought-implies-can principle: (OIC) by virtue of conceptual necessity, an agent at a given time has an (objective, pro tanto) obligation to do only what the agent at that time has the ability and opportunity to do. In short, obligations correspond to ability plus opportunity. My argument has three premises: (1) obligations correspond to reasons for action; (2) reasons for action correspond to potential actions; (3) potential actions correspond to ability plus opportunity. In the (...) bulk of the paper I address six objections to OIC: three objections based on putative counterexamples, and three objections based on arguments to the effect that OIC conflicts with the is/ought thesis, the possibility of hard determinism, and the denial of the Principle of Alternate Possibilities. (shrink)

I argue for a version of "ought" implies "can". In particular, I argue that it is necessarily true that if an agent, S, ultima facie ought to do A at T', then there is a time T* such that S can at T* do A at T'. In support of this principle, I have argued that without it, we cannot explain how it is that, in cases where agents cannot do the best thing, they often ought to do some alternative (...) action - such as get help or do the promised action later; nor can we explain the phenomenon of necessary enablers or the phenomenon of more stringent prima facie obligations overriding less stringent ones in cases where the agent cannot fulfill both. (shrink)

A type of transcendental argument for libertarian free will maintains that if acting freely requires the availability of alternative possibilities, and determinism holds, then one is not justified in asserting that there is no free will. More precisely: if an agent A is to be justified in asserting a proposition P (e.g. "there is no free will"), then A must also be able to assert not-P. Thus, if A is unable to assert not-P, due to determinism, then A is not (...) justified in asserting P. While such arguments often appeal to principles with wide appeal, such as the principle that ‘ought’ implies ‘can’, they also require a commitment to principles that seem far less compelling, e.g. the principle that ‘ought’ implies ‘able not to’ or the principle that having an obligation entails being responsible. It is argued here that these further principles are dubious, and that it will be difficult to construct a valid transcendental argument without them. (shrink)

Haji argues that determinism threatens deontic morality, not via a threat to moral responsibility, but directly, because of the principle that ‘ought’ implies ‘can’. Haji’s argument requires not only that we embrace an ‘ought’ implies ‘can’ principle, but also that we adopt the principle that ‘ought’ implies ‘able not to’. I argue that we have little reason to adopt the latter principle, and examine whether deontic morality might be destroyed on the basis of the more commonly embraced ‘ought’ implies ‘can’ (...) principle alone. I argue that despite what look like initially compelling reasons why we might suppose that this weaker conclusion is similarly destructive to deontic morality, we actually have good reason to doubt that it has any practical relevance for moral deliberation at all. (shrink)