The interesting thesis, for contemporary Humeans, in Part i of Book III of the Treatise is Hume's account of moral belief (broad sense), i.e., his sentimentalism, as some have called it. Hume's account has two parts. The basic, most argued for, part is a negative account of moral belief (III,i,l). It makes a claim about what moral judgments are not. They are not ‘deriv'd from reason’. I have argued that this negative claim is non-cognitivism (unless it is a highly subjectivist cognitivism). The positive thesis (III,i,2) is an account of what moral beliefs are. They are, or express, or centrally involve, the having of special sentiments (unless, perhaps, they are noninferential cognitive beliefs about one's having sentiments).

Sentimentalism is a meta-ethical thesis, at least in the broadest sense of ‘meta-ethical’, for it is a claim about the nature of moral judgments and not (obviously, at any rate) itself one of the substantive moral judgments it is about.