The aim of this thesis is to outline a plausible metaethical framework. The inspiration for this project is a desire to respond to the moral error theory of Richard Joyce and John Mackie, and to offer a version of moral success theory not subject to the same sceptical attacks.1 Joyce's and Mackie's error theory may be summarised as follows: morality is (or purports to be) normative in a kind of way that turns out to be problematic and which renders all moral judgments false.2 What I intend to do is present an underexplored (but not all together new) way of understanding the normativity of morality, and, from this, to develop an account of the conditions under which moral judgments are true. This thesis is an ambitious one given that the four central chapters (2-5) each address a different major question, each of which is pertinent to the aims of this project. Chapter 2 will address the question of which of the two major competing theories of practical rationality (internalism and externalism) is superior