  There is little controversy about the existence of widespread disagreement over moral issues, both within and between societies and cultures. Often used examples are the debates about the morality of the death penalty, of euthanasia, of abortion, and of meat-eating. Examples of cultural differences include infanticide and geronticide and other more or less alien practices that historians and anthropologists have revealed. For example, Napoleon Chagnon’s account of the ways of the Yanomamö people in the Amazon basin is a popular source of illustrations (Chagnon 1997, but see also Tierney 2003 for a critical discussion). Some theorists assign special weight to disagreements among philosophers and professional ethicists who have engaged in systematic reflection about moral issues (e.g., Wong 1984, ch. 10 and Leiter 2014). What they have in mind are, among other disputes, those between utilitarians and Kantians about what makes an action morally right and those between egalitarians and libertarians about what justice requires. How deep the disagreement goes, however, and how it is best explained, are disputed questions. So is another topic which in a way precedes the others, namely, what it is, more specifically, to disagree morally.