There are good reasons to consider Hume to have been a moral relativist. There are also good reasons to deny that he was one. Hume answered the question of the Euthyphro in the negative: a divine being could feel no sentiments, so could feel no moral sentiments, and so could have no moral sense. Morality, like secondary qualities, is something that exists for creatures and that is brought about by making those creatures a certain way. At the same time, Hume was concerned to argue that, as a matter of fact, human beings all share a common sentimental constitution that makes them all value what is useful or agreeable either to self or others. The issue of moral disagreement is a challenge to this conclusion. But Hume sought to address it only to the extent that it is a challenge. Moral disagreements that arise from prioritizing different utilities, or giving different weight to the useful as opposed to the agreeable or the personal as opposed to the social, are not ones he was concerned to resolve or adjudicate, though he did think that our moral psychology would not allow us to tolerate one another’s contrary opinions on these matters.

Interest in what has been called a ‘moral sense’ originated in the late 17th century, as part of a philosophical debate about humans’ moral nature. Participants in the debate agreed on rejecting four views of human morality commonly held at the time. They found (1) the Cambridge Platonists’ moral rationalism and (2) Gershom Carmichael’s (and others’) natural law theories of morality too remote from actual processes of moral judgment and decision making; (3) they rejected Thomas Hobbes’ psychological egoism as excessively reductive; and (4) they found moral relativism objectionable on normative grounds, since they were committed to the defence of moral universalism. The article provides an overview over the history of moral sense theories. It briefly presents the versions developed by Thomas Burnet, Anthony Ashley-Cooper, 3rd Earl of Shaftesbury, Francis Hutcheson, Joseph Butler, and Henry Home Lord Kames, and then provides a brief account of the moral theories by David Hume and Adam Smith who, while adherents of moral sentimentalism, rejected the assumption of a moral sense.