ABSTRACT
Abstract. Suppose that the human tendency to think of certain actions and omissions as morally required - a notion that surely lies at the heart of moral discourse - is a trait that has been naturally selected for. Many have thought that from this premise we can justify or vindicate moral concepts. I argue that this is mistaken, and defend Michael Ruse's view that the more plausible implication is an error theory - the idea that morality is an illusion foisted upon us by evolution. The naturalistic fallacy is a red herring in this debate, since there is really nothing that counts as a 'fallacy' at all. If morality is an illusion, it appears to follow that we should, upon discovering this, abolish moral discourse on pain of irrationality. I argue that this conclusion is too hasty, and that we may be able usefully to employ a moral discourse, warts and all, without believing in it.
