Naturalizing Metaethics

Decades ago, it was suggested that epistemology could be naturalized, meaning, roughly, that it could be treated as an empirically-informed psychological inquiry. In more recent years, there has been a concerted effort to naturalize ethics, with a focus on questions in moral psychology, and occasional normative ethics. Less effort has been put into the naturalization of metaethics: the study of what, if anything, makes moral judgments true. The discussion presents a systematic overview of core questions in metaethics, and argues that each of these can be illuminated by psychological research. These include questions about realism, expressivism, error theory, and relativism. Metaethics is beholden to moral psychology, and moral psychology can be studied empirically. The primary goal is to establish empirical tractability, but, in so doing, the paper also takes a provisional stance on core questions, defending a view that is relativist, subjective, and emotionally grounded.