  Blackburn’s favored explanation of the difference in status between the two claims is roughly as follows: Moral judgments must supervene on judgments regarding natural properties because it is the point of moral judgments “to guide desires and choices among the natural features of the world” (Blackburn 1993, 137). Since this sort of explanation makes reference to our purposes in using moral terms rather than to an independent realm of moral fact, Blackburn thinks it supports a quasi-realist account rather than a straightforward realist theory. He goes on to suggest that because the explanation relies on facts about what beliefs can coexist with linguistic competence, there is “no further inference to a metaphysical conclusion” (Blackburn 1993, 143).