Abstract
Suppose that the human tendency to think of certain actions andomissions as morally required – a notion that surely lies at the heart of moral discourse – is a trait that has been naturallyselected for. Many have thought that from this premise we canjustify or vindicate moral concepts. I argue that this is mistaken, and defend Michael Ruse's view that the moreplausible implication is an error theory – the idea thatmorality is an illusion foisted upon us by evolution. Thenaturalistic 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 followthat we should, upon discovering this, abolish moraldiscourse on pain of irrationality. I argue that thisconclusion is too hasty, and that we may be able usefullyto employ a moral discourse, warts and all, withoutbelieving in it.