Introduction Neil Sinclair; 1. The naturalistic fallacy and the history of metaethics Neil Sinclair; 2. The naturalistic fallacy: what it is, and what it isn't Fred Feldman; 3. The context and origin of Moore's Formulation of the Naturalistic Fallacy in Principia Ethica Consuelo Preti; 4. No-ought-from-is, the naturalistic fallacy and the fact/value distinction: the history of a mistake Charles Pigden; 5. Evolution and the naturalistic fallacy Michael Ruse; 6. Motivation, recommendation, non-cognitivism and the naturalistic fallacy Mark van Roojen; 7. Open question arguments and the irreducibility of ethical normativity William J. FitzPatrick; 8. Should analytical descriptivists worry about the naturalistic fallacy? Susana Nuccetelli; 9. Normativity and the naturalistic fallacy Connie S. Rosati; 10. The naturalistic fallacy and theological ethics Christian B. Miller; 11. The phenomenology of moral deliberation and the non-naturalistic fallacy Terry Horgan and Mark Timmons; 12. Epistemic relativism and the naturalistic fallacy J. Adam Carter.