I was criticized after my post on vegetarianism for sneaking an ethical subtext into what was ostensibly a post about killing animals. So to clear up all doubt, I will be completely straightforward now with what I believe about morality:
Morality does not exist in the world. It is not logical. There is no such thing as a true or false moral statement. And it is impossible to rationally persuade someone of a moral conviction that he does not already hold.
I want to distinguish morality here from what I'll call ethical norms. By norms, I mean codes of behavior that human beings enforce—both socially and legally—in much the same way as they enforce rules of language. Norms are abundant in the world. It is an empirical fact that if I walk down the streets of Teheran with a bottle of brandy, I will be punished. If I hit someone with a baseball bat in Hyde Park, I will not only go to jail but also lose favor among my friends. Norms vary from place to place, but most societies on earth have many precepts in common. This is partly because in general, human beings have good reason to try to prevent things like premeditated murder.
But norms like this are not what people usually mean when they call something immoral. Morality, rather, refers to what people think is the essential badness or goodness of a thing. Morality is what makes it just-plain-wrong to murder and lie, wherever I am.
The problem, though, is that this kind of essential badness is not something we can point to or whose existence we can test. We can only make testable, meaningful statements about the way things are in the world. Here's a bird, there's a pebble. There's a bird eating a pebble. Here's the Biblical prohibition of sodomy, there's Lawrence v. Texas. There's a California legislator defying both. But a moral statement is not a description of the way things are. As Wittgenstein said, if I wrote a scientific history of everything; describing the whizzing of the stars, the composition of the earth, and the history of human beings; nowhere in my enormous book would there be a single normative sentence.
So whatever moral values there are, they have nothing to do with the way the world appears. They have everything to do with what the world means—and that's not an question that can be answered with an informed rational discussion. Morals are, as Ludwig Wittgenstein said, mystical.
I should be clear about the implications of what I am saying. If I am asked: why it is immoral to murder a baby? I will have no answer. I won't even know where to start.
Let me illustrate my point with this dialogue between Joe, who's gay, and a homophobic Republican:
Republican: Your way of life is immoral and an offense to decency.
Joe: Says who? You have no right to impose your morality on me.
R: You are imposing your morality on me when you insist on this arbitrary principle of non-intervention.
J: All I'm saying is that whatever consenting adults do behind closed doors is none of your business.
R: Morality is of course my business. And what difference does it make if you sin in private? By the way, how do you know that consent is the criterion of morality?
And so on. To give another example, f I had been born in pre-modern Igboland, I would have been condemned to death for being a twin. If I had cried: stop! you are acting immorally! I would have received the response: your very existence is what's immoral. And there would have been no judge on Earth to tell us who was right. To arbitrate the dispute would mean talking about things that do not exist in the world—and that is something that our language is incapable of doing.
None of this means that I do not have moral convictions or try to act morally. But morality is something that I simply practice, not something I can reasonably defend against someone who disagrees with me.
Doesn't this make you a cultural relativist? In one sense yes, and in another no. It is an empirical fact that different societies have different norms, and also that societies (and people, for that matter) often attempt to impose their norms on each other. But I do not derive from that fact any moral duty to respect the norms of any given society or person. In fact, I believe that I am morally obligated to reject the cultural norms that I think are immoral. It was appropriate, for instance, for the British government to ban the Rajasthani practice of widow-burning.
Are you a post-modern nihilist? To the contrary! I believe that I am commanded to live for other people and not for my belly. The problem is that I can neither talk sensibly about this commandment nor convince you of it: it does not exist in the world. (On the other hand, the absence of morality in the world means that it is conceivable for a person to run joyfully down the road to hedonism without stumbling.)
Don Giovanni stumbles.