  Moral naturalism is an attractive view. As a form of realism, it offers to make robust sense of moral objectivity and moral knowledge, allowing for moral utterances to be truth-apt in straightforward ways and for some of them to be true. And as a form of naturalism it is widely seen as preferable to rival forms of moral realism. Moral properties and facts, realistically construed, can often seem unpalatably “queer”, as Mackie famously expressed it (Mackie 1977, chapter 1, section 9): a realist can seem committed to the existence of metaphysically far out entities or properties and embarrassed by the lack of any plausible epistemic story of how we can obtain knowledge of them. The naturalist offers to save realism but eliminate the mystery.