A standard principle in ethics is that moral obligation entails ability, or that “ought implies can”. A strong case has been made that this principle is not well motivated in moral psychology. This paper presents an analogous case against the theoretical motivation for the principle. The principle is in tension with several foundational areas of ethical theorizing, including research on apologies, excuses, promises, moral dilemmas, moral language, disability, and moral agency. Across each of these areas, accepting the principle that obligation (...) entails ability creates a theoretical problem that is more easily solved by rejecting it rather than accepting it. I conclude that the motivation for the principle is weak and that “ought implies can” should be rejected in ethics on theoretical grounds. (shrink)

While philosophers generally accept some version of the principle ‘ought’ implies ‘can’, recent work in experimental philosophy and cognitive science provides evidence against a presupposition or a conceptual entailment from ‘ought’ to ‘can’. Here, we review some of this evidence, its effect on particular formulations of the principle, and future directions for cognitive scientists and philosophers.

Many philosophers claim that ‘ought’ implies ‘can’. In light of recent empirical evidence, however, some skeptics conclude that philosophers should stop assuming the principle unconditionally. Streumer, however, does not simply assume the principle’s truth; he provides arguments for it. In this article, we argue that his arguments fail to support the claim that ‘ought’ implies ‘can’.