Must Metaethical Realism Make a Semantic Claim?

Mackie drew attention to the distinct semantic and metaphysical claims made by metaethical realists, arguing that although our evaluative discourse is cognitive and objective, there are no objective evaluative facts. This distinction, however, also opens up a reverse possibility: that our evaluative discourse is antirealist, yet objective values do exist. I suggest that this seemingly far-fetched possibility merits serious attention; realism seems committed to its intelligibility, and, despite appearances, it isn’t incoherent, ineffable, inherently implausible or impossible to defend. I argue that reflection on this possibility should lead us to revise our understanding of the debate between realists and antirealists. It is not only that the realist’s semantic claim is insufficient for realism to be true, as Mackie argued; it’s not even necessary. Robust metaethical realism is best understood as making a purely metaphysical claim. It is thus not enough for antirealists to show that our discourse is antirealist. They must directly attack the realist’s metaphysical claim.