Is-Ought Problem

The is-ought problem asks whether moral statements about what ought to be can be validly inferred from purely descriptive statements about what is the case. It was first articulated by the eighteenth-century Scottish philosopher David Hume, who held that there is a significant gap between descriptive and prescriptive statements and that it is not obvious how one can coherently move from the former to the latter; this thesis is often called Hume's law or Hume's guillotine. A related argument is G.E. Moore's open question argument, which similarly resists any identification of moral properties with natural properties. The is-ought problem is closely tied to the fact-value distinction, and academic discussion of that broader distinction can extend beyond ethics into aesthetics.