In general, philosophers deem the importance of skepticism to be merely methodological, that is, they regard skeptical arguments as useful tools for their inquiries. It is important to make clear the range of views that are taken as varieties of moral scepticism. This chapter describes a possible general formulation of the moral anti-realist's ontological skepticism. The claim that moral judgments are not assertions that convey beliefs, despite their being usually expressed in the indicative mood, is what distinguishes moral noncognitivism from moral error theory. One must suspend judgment about whether moral knowledge is possible and about whether any moral belief is epistemically justified. It is nihilistic epistemological moral skepticism that has been more commonly discussed in the contemporary metaethical literature. However, Pyrrhonian skepticism has slowly but increasingly been taken into consideration, perhaps due to the fact that it has, for some time now, been the focus of much attention in epistemology.