Akhlaghi 1 has recently presented a novel challenge against realist moral naturalism and moral non-cognitivism. The challenge builds upon the putative difficulty of both realist moral naturalism and non-cognitivism to accommodate the epistemic possibility of wholesale moral error. The argument is the following: 2 (P1) It is an epistemic possibility that morality is subject to some wholesale error that would make the moral error theory true.(P2) If (P1), then it is an adequacy condition on meta-ethical theories that they allow for and explain the epistemic possibility of such error.(P3) Non-cognitivism and moral naturalism cannot allow for and explain the epistemic possibility of such error.