Relativism Is Still Hard
Allegation: Relativism entails that anything goes.
Response: Relativists concede that if you were to inculcate any given set of values, those values would be true for those who possessed them. But we have little incentive to inculcate values arbitrarily. If we trained our children to be ruthless killers, they might kill us or get killed. Values that are completely self-destructive can’t last.
The logical implication that relativism means anything goes is not rebutted by pointing to the empirical fact that few people have an actual incentive to inculate intuitively horrifying values. The point is that if some psychopath did decide to inculate such values anyway, morality would give us no way to say they shouldn't do that. Prinz assures us that self-destructive values can't last. But other-destructive values certainly can last. And values that are self-harming but not "completely self-destructive" are not weeded out in this way either. Moreover, why should we care whether a set of values can last? A relativist has no response to someone who says "the heck with lasting -- I want humanity to go out in a blaze of violent genocide!"
Allegation: Relativism entails that we have no way to criticize Hitler.
Response: First of all, Hitler's actions were partially based on false beliefs, rather than values ('scientific' racism, moral absolutism, the likelihood of world domination). Second, the problem with Hitler was not that his values were false, but that they were pernicious. Relativism does not entail that we should tolerate murderous tyranny. When someone threatens us or our way of life, we are strongly motivated to protect ourselves.
So our relativist says to Hitler, "your beliefs are based on false science." Hitler, having also come around to see the truth of relativism, replies "so what? Why should I care about scientific accuracy? I value beliefs that comfort my prejudices more than I value beliefs that are true."
More importantly, here we see Prinz get more explicit about the backdoor moral values he hinted at in his focus on not being self-destructive in the previous point. What does it mean to say something is "pernicious" if not to pass a moral judgment on it? Hitler certainly didn't think his values were pernicious -- quite the opposite, he thought he was saving the world from the evils of the Jews, communists, and others. So sure, relativism doesn't entail that we should tolerate murderous tyranny, but neither does it tell us we shouldn't tolerate murderous tyranny. Relativism leaves it up to our personal preference. So my Jewish friends are free, in a relativistic world, to prefer to defend themselves -- but I am equally free to say "you know, as a blue-eyed able-bodied guy, I'd actually prefer to join some similar folks in exterminating people who are not like me."
Allegation: Relativism entails that moral debates are senseless, since everyone is right.
Response: This is a major misconception. Many people have overlapping moral values, and one can settle debates by appeal to moral common ground. We can also have substantive debates about how to apply and extend our basic values. Some debates are senseless, however. Committed liberals and conservatives rarely persuade each other, but public debates over policy can rally the base and sway the undecided.
This point I mostly agree with -- moral argument makes sense only when there are some shared premises or axioms that each side can try to leverage to sway the other. As long as people hold shared premises they can agree to take those as a starting point and argue from there.
Allegation: Relativism doesn't allow moral progress.
Response: In one sense this is correct; moral values do not become more true. But they can become better by other criteria. For example, some sets of values are more consistent and more conducive to social stability. If moral relativism is true, morality can be regarded as a tool, and we can think about what we'd like that tool to do for us and revise morality accordingly.
But social stability is itself a value! Perhaps I don't care about social stability, and have no interest in promoting it. Even consistency is a value, and therefore could be freely rejected in a relativistic world. Indeed, I have encountered plenty of people who revel in their inconsistency, and see a demand to make their beliefs consistent as a smallness of mind and tyrannical oppression.
... The discovery that relativism is true can help each of us individually by revealing that our values are mutable and parochial. We should not assume that others share our views, and we should recognize that our views would differ had we lived in different circumstances. These discoveries may make us more tolerant and more flexible. Relativism does not entail tolerance or any other moral value, but, once we see that there is no single true morality, we lose one incentive for trying to impose our values on others.
There are two claims being made here. One is that embracing relativism will in fact make us more tolerant and humble, and deflate our desire to impose morality on others. This may be the case for many people. But I can as easily imagine someone saying "I value X. Relativism tells me that nobody else's values that run counter to X are any more valid or true. So there is nothing standing in my way if I want to go ahead and impose X on others and run roughshod over their resistance to my attempts to create an X-full world."
The other claim is that this is a good thing. I'm sure Prinz and Wilkinson value a more tolerant world, and I do too. But again, relativism entails that that is just our preference. Given that there are many people who value intolerance, it's not true that acceptance of relativism "can help each of us individually."
I should be clear that this post does not constitute a case for moral objectivism. Indeed, I don't believe a case for moral objectivism can be made in the abstract -- all that can be made is a case that one particular moral system is in fact objectively correct. But I think acceptance of relativism has somewhat more radical consequences than Prinz and Wilkinson want to admit.