Why metaethics needs empirical moral psychology

What is the significance of empirical moral psychology for metaethics? In this article we take up Michael Ruse's evolutionary debunking argument against moral realism and reassess it in the context of the empirical state of the art. Ruse's argument depends on the phenomenological presumption that people generally experience morality as objective. We demonstrate how recent experimental findings challenge this widely-shared armchair presumption and conclude that Ruse's argument fails. We situate this finding in the recent debate about Carnapian explication and argue that it illustrates the necessary role that empirical moral psychology plays in explication preparation. Moral psychology sets boundaries for reasonable desiderata in metaethics and, therefore, it is necessary for metaethics.