Philosophers have urged that considerations about the psychopath’s capacity for practical rationality can help to advance metaethical debates. These debates include the role of rational faculties in moral judgment and action, the relationship between moral judgment and moral motivation, and the capacities required for morally responsible agency. I discuss how the psychopath’s capacity for practical reason features in these debates, and I identify several takeaway lessons from the relevant literature. Specifically, I show how the insights contained therein can illuminate the (...) complex structure of practical rationality, inform our standards for an adequate theory of practical reason, and frame our thinking about the significance of rational capacities in moral theory and social practice. (shrink)