One's sentiments are the contents of one's sensed, or felt, experience—in contrast to the contents of simply one's thoughts. Whatever else they are, then, sentiments are affective phenomena. In common parlance, talk of sentiments refers alternatively to occurrent feelings, affective dispositions, and emotional attitudes taken toward people and objects. Moral sentiments, where the adjective moral is used in a descriptive sense, would then be some subset of these feelings, dispositions, and attitudes: those that are more or less intimately related to moral phenomena. Whether any of the moral sentiments thus understood are moral in a normative sense, that is, whether one morally may or should experience or express any of these sentiments in relevant circumstances, is a further question.

One problem that immediately confronts any philosophical account of moral sentiments is the question whether such affective phenomena in fact form a unified category. Affective responses...