Let's assume that we are confronted with an early 20th-century American racist. Assume this person is a segregationist who believes that blacks and whites should not live together, go to school together, or marry. What can the ethical relativist, using the methods of Regan and Rawls, say in reply?

• First, consider the question of conceptual clarity. Some anthropologists question whether the concept of race is sufficiently clear to be used as a scientific concept. I'm not an anthropologist, but my point is that the very concept of race may not pass Regan's test of conceptual clarity.
• Second, consider impartiality. From moral philosophy we get the principle that equal cases should be treated equally. This is a purely formal principle that most moral philosophers accept. By itself, it tells us nothing about what is good or bad, right or wrong. But if we accept this principle, we are committed to the view that two actions cannot be exactly the same in all relevant respects except that one is good (right) and one is bad (wrong). We can use this principle. It forces the racist to show how the cases of blacks and whites are different in order to justify different treatment.
• Third, consider whether racism is consistent with the best social and psychological science available. When asked for reasons to support his claim that blacks and whites should be treated differently, the racist will typically claim that blacks and whites have different capacities and propensities. These differences justify treating their cases differently. For example, difference in intelligence makes it impractical to educate blacks and whites together. As far as marriage is concerned, he may argue that if blacks and whites marry, the children will be degenerate in some respects. Again, this justifies treating the case of a mixed marriage differently from one that is not mixed. >But I would claim that the best social, psychological, and medical science provides evidence to refute these claims about racial differences.

In short, I think the ethical relativist can use some of the ideas of Rawls and Regan to argue effectively against racism and racial discrimination.