There is a sleight of hand that happens in news articles, political debates, and family arguments: a speaker lays out a list of facts and then, without anyone noticing, slips in a demand about what you must do. This episode explores the is-ought problem, first exposed by David Hume in his 1739 Treatise of Human Nature, and asks whether it is ever logically possible to derive what we ought to do from what is.

We walk through Hume's fork and Hume's guillotine, G.E. Moore's open question argument, and the slide into moral skepticism and non-cognitivism. Then we test the bridges philosophers have built: Alasdair MacIntyre's scissors and Arthur Prior's sea captain, the poisoner dilemma and the unempathetic citizen Alice, G.E.M. Anscombe's proposal to abandon the moral ought, John Searle's institutional facts and promises, Philippa Foot's argumen ...