This paper takes up an important epistemological challenge to the naturalistic moral realist: that her metaphysical commitments are difficult to square with a plausible rationalist view about the epistemology of morality. The paper begins by clarifying and generalizing this challenge. It then illustrates how the generalized challenge can be answered by a form of naturalistic moral realism that I dub joint-carving moral realism. Both my framing of this challenge and my answer advertise the methodological significance of non-fundamental epistemological theorizing, which (...) defends and deploys epistemological claims without adverting to the most fundamental epistemological facts. (shrink)