 David Hume generated a popular controversy with his famous passages of “A Treatise of Human Nature” (see Hume 2000: Book 3, Part 1, Section 1, paragraph 27) where he noted that sometimes people draw conclusions involving prescriptive statements of the form ‘ought to be’ on the basis of descriptive statements of the form ‘what is’. Hume thinks that logic used in this way involves a dangerous change of subject matter. So, whether or not ‘ought’ can be derived from ‘is’ has become one of the central questions of ethical theory, and the majority of interpreters hold that, for Hume, such a derivation is impossible.