The limits of the just-too-different argument

According to moral non-naturalism, the kind of genuine or robust normativity that is characteristic of moral requirements cannot be accounted for within a wholly naturalistic worldview, but requires us to posit a domain of non-natural properties and facts. The main argument for this core non-naturalist claim appeals to what David Enoch calls the 'just-too-different intuition'. According to Enoch, robust normativity cannot be natural, since it is just too different from anything natural. Derek Parfit makes essentially the same claim under the heading of 'the normativity objection', and several other non-naturalists have said similar things. While some naturalists may be tempted to reject this argument as methodologically or dialectically illegitimate, we argue instead that there are important limits to what the just-too-different intuition can show, even setting all other worries aside. More specifically, we argue that the just-too-different argument will backfire on any positive, independent specification of the distinction between the natural and the non-natural. The upshot is that the just-too-different argument can show significantly less than non-naturalists have suggested.