Most philosophers assume that ‘ought’ implies ‘can’, and most of them hold that this principle is true not only universally but also analytically or conceptually. Some skeptics deny this principle, although they often admit some related one. In this article, we show how new empirical evidence bolsters the skeptics’ arguments. We then defend the skeptical view against some objections to the empirical evidence and to its effect on the traditional principle. In light of the new evidence, we conclude that philosophers (...) should stop unconditionally assuming that ‘ought’ implies ‘can’. (shrink)

Many metaphysical controversies can be understood as debates over whether some alleged entities are metaphysically possible. No doubt, with regard to these matters, we may have opinions or theories, commonsensical or sophisticated. But do we have knowledge of them? Can we really know that something is metaphysically possible, and if so, how? Several different answers have been offered in the literature, intending to illustrate how we may have knowledge of metaphysical modality. In this paper, I concentrate on a proposal by (...) Timothy Williamson. On this account, our alleged knowledge of metaphysical modality is justified by and grounded in our capacity to handle ordinary mundane counterfactual conditionals. However, I argue that Williamson’s account fails, mainly because the modality involved in ordinary mundane counterfactuals is causal, and thus our capacity to handle them still falls short of giving us any knowledge of metaphysical modality. In the end of the paper, I also provide my own answer to the question. My answer is a sceptical one: we do not really have knowledge of metaphysical modality. But such ignorance is harmless, or so I argue. (shrink)