 The most extensive appeal to empirical work on the moral/conventional distinction in the philosophical literature has been in the intertwined debates over moral internalism and the moral responsibility of psychopaths. To explain these debates, a bit of background is needed. When someone judges that an action is the morally right or morally required thing to do it is often the case that she goes on to do it. Why? What is her motivation for doing what she judges to be morally required? From the ancient Greeks onward, philosophers have been interested in moral motivation, and in recent decades debates over the nature of moral motivation have played a prominent role in metaethics. One central component in this multi-faceted discussion is the debate between various versions of internalism, which hold