We should reject moral relativism. A much better case against cultural imperialism can be made from the standpoint of a view of ethics that allows for the possibility of moral argument beyond the boundaries of one's own culture. Then we can argue that distinctive cultures embody ways of living that have been developed over countless generations, that when they are destroyed the accumulated wisdom that they represent is lost, and that we are all enriched by being able to observe and appreciate a diversity of cultures.
(Peter Singer, One World: The Ethics of Globalization, The Terry Lectures [New Haven and London: Yale University Press, 2002], 140)
Note from KBJ: In 1974, Singer was less sanguine about "accumulated wisdom":
Why should we not rather make the opposite assumption, that all the particular moral judgments we intuitively make are likely to derive from discarded religious systems, from warped views of sex and bodily functions, or from customs necessary for the survival of the group in social and economic circumstances that now lie in the distant past? In which case it would be best to forget all about our particular moral judgments, and start again from as near as we can get to self-evident moral axioms. (Peter Singer, "Sidgwick and Reflective Equilibrium," The Monist 58 [July 1974]: 490-517, at 516)
To be fair to Singer, he does not say, in One World, that the "accumulated wisdom" of "distinctive cultures" must be uncritically accepted. But he does call it "accumulated wisdom," which implies that it deserves respect. In 1974, he seems unwilling to say even that much. Could it be that Singer thinks there is "accumulated wisdom" in other cultures, but not in ours? But why would that be? Is it not possible that the "sanctity of human life" doctrine that Singer so despises embodies a way of living that has been "developed over countless generations"? Is it not, therefore, deserving of at least some degree of respect? Isn't it dangerous as well as arrogant to dismiss the doctrine as the product of "discarded religious systems"? (Discarded by whom? Does Singer not realize that the overwhelming majority of people on this planet are religious?) Far from respecting the "sanctity of human life" doctrine, Singer thinks it is the source of many of our most pressing moral problems. If he could snap his fingers and do away with it, he would.
