Antti Kauppinen reviews J. David Velleman, Foundations for Moral Relativism, in Notre Dame Philosophical Reviews:
It comes as no surprise that David Velleman's brief but dense new book is original, provocative, erudite, and seductive. Drawing on a characteristically broad range of non-philosophical sources — such as game studies, anthropology, and ethnomethodology — he presents novel arguments in defense of moral relativism. In this review, I will examine some of his central arguments.
What is moral relativism? It is not the view that different things are morally right or wrong in different circumstances. Non-relativists agree that whether it is wrong to let a child play alone in the park or dance at a funeral depends on whether there is a risk of significant harm or whether the behavior is disrespectful in context. What they insist on is that context-dependent truths about right and wrong can be derived from the conjunction of non-moral facts of the situation and basic moral principles that are universal in the sense that they apply to everyone regardless of their moral or other beliefs or community membership. This is what relativism denies. Positively, relativism says that there are a variety of communities whose norms are genuinely authoritative for their members.
One way to put the relativist claim is semantic. Velleman says that “it makes no sense to ask whether an action or practice is wrong simpliciter” (45), any more than it makes sense to ask whether someone is tall simpliciter. Just like someone can only be tall-for-X, something can only be wrong-for-members-of-X (or perhaps wrong-by-the-standards-of-X). In each case, the variable may be left implicit to be supplied by the context. Famously, such views have difficulty accommodating the intuition that it's possible for people in different communities (or just people subscribing to different moral standards) to disagree with each other without linguistic confusion. The Catholic from Peru who says that abortion is always wrong and the atheist from Sweden who says it is not always wrong appear to hold conflicting views on the morality of abortion, rather than just making claims about what their own standards or communal norms prohibit or allow.
I suspect Velleman would say that such disagreement is only genuine insofar as the parties are members of the same community (in spite of their differences). Otherwise, they will be speaking past each other after all — their only disagreement can be in attitude, in what to do. (Velleman has no patience for recently trendy forms of relativism, according to which it is possible for people to disagree faultlessly.) Were they to confusedly maintain that abortion is wrong or not wrong simpliciter, they would be mistaken. Why? According to Velleman, the main argument against universalism is simple: there are communities with different moral norms, and “no one has ever succeeded in showing any one set of norms to be universally valid” (45).