Is–ought problem

The is–ought problem is the question of whether moral statements about what ought to be can be inferred from objective statements about what is. It was first articulated by the 18th-century Scottish philosopher David Hume, who saw a significant difference between descriptive statements (about what is) and prescriptive statements (about what ought to be). He argued that it is not obvious how one can coherently transition from descriptive statements to prescriptive ones. Hume's law or Hume's guillotine is the thesis that an ethical or judgemental conclusion cannot be inferred from purely descriptive factual statements. A similar view is defended by G. E. Moore's open-question argument, intended to refute any identification of moral properties with natural properties, which is asserted by ethical naturalists, who do not deem the naturalistic fallacy a fallacy. The is–ought problem is closely related to the fact–value distinction in epistemology. Though the terms are often used interchangeably, academic discourse concerning the latter may encompass aesthetics in addition to ethics.