Abstract
This paper presents a discussion of an apparent inconsistency between Hume's moral theory and his moral evaluations of historical characters in his History of England. While Hume considers enthusiasm to be a religious vice, he praises the characters of some historical enthusiasts, blames others, and regards enthusiasm as having a positive social effect. But according to Hume's moral theory, only a virtue can have positive social effect, or be praiseworthy. The paper refers to the inconsistency between the History and the moral theory as the ‘enthusiasm puzzle’. The paper concludes by explaining the inconsistency as being rooted in a problem with Hume's moral theory