In this essay, I consider whether the alleged demise of metaphysical realism does actually provide a better way for defending the cognitive status of ethical judgments. I argue that the rejection of a realist ontology and epistemology does not help to establish the claim that ethical knowledge is possible. More specifically, I argue that Hilary Putnam's argument does not succeed in making a case for ethical knowledge. In fact, his account of the procedures by which our valuations are warranted—the criteria (...) of idealized inquiry—ultimately begs the question in a number of crucial ways. Moreover, it prejudices the moral and political discussion in certain ideological respects. Finally, though Putnam has apparently modified to some extent his approach to the issue of realism in recent years, I will point out that these modifications are not fundamental and do not help to advance the case for ethical knowledge. I note also that Martha C. Nussbaum's appeal to Putnam’s argument actually works against her attempt to make a case for an Aristotelian conception of human flourishing. Ultimately, I conclude that metaphysical realism is vital for ethical knowledge. (shrink)