The Naturalistic Fallacy

The ‘naturalistic fallacy’ has been variously identified with the claim that: (i) moral concepts can be defined in terms of non-moral, natural, or metaphysical concepts (the semantic form of the fallacy), (ii) moral properties can be identified with complex, non-moral, natural, or metaphysical properties (the ontological form), (iii) substantive moral conclusions (‘oughts’) can be derived from wholly non-moral premises (‘is-es’; the inferential or Humean form of the fallacy). The phrase was coined by Moore, who did not sharply distinguish between concepts and properties, and who focused on goodness, which he took to be fundamental and simple. Moore’s argument for thinking that the fallacy is a fallacy (i.e. false) is the open question argument. Replies to Moore include the claim that his argument begs the question, that it precludes any informative analysis (the paradox of analysis) and that it establishes only the indefinability of moral concepts, not the irreducibility of moral properties.   

Moore introduces the naturalistic fallacy in Moore 1903 (section 10), although he later expressed dissatisfaction which his formulation there, and tried to improve on it in a preface to a never-completed second edition (reprinted in Baldwin 1993). Frankena 1939 argues that Moore’s argument is question-begging; Snare 1975 responds. Jackson 1998 (chapter 6) and Smith 1994 (chapter 2) defend analytic naturalism against Moore, highlighting Moore’s paradox of analysis. Durrant 1970 is an early statement of a view which accepts the indefinability of moral concepts but not the irreducibility of moral properties – pursued at length in Boyd 1988. Darwall et al 1992 provides an overview of the influence of Moore’s arguments on metaethics and Baldwin 1990 (chapter 3) gives a detailed account how the fallacy fits in to Moore’s wider philosophical views. A forthcoming collection is Sinclair 2018.