In metaethics, empirical approaches are not just complementary to, but continuous with, traditional approaches to the subject. This chapter addresses traditional and empirical approaches to metaethics. It discusses how empirical approaches have been brought to bear on some central metaethical questions. The chapter illustrates not just the diversity of topics within metaethics itself but also the diversity of empirical methods and approaches that philosophers and psychologists working on these topics are using. The debate between internalists and externalists is a debate concerning the psychology of moral judgment, but also a debate about our concept of moral judgment. As such, it has implications for other metaethical debates. Antirealists such as relativists and noncognitivists often defend internalism, and argue that their views are best equipped to explain the link between moral judgment and motivation.