Yet tolerance by itself is not what distinguishes the cosmopolitan from the neofundamentalist. There are plenty of things that the heroes of radical Islam are happy to tolerate. They don't care if you eat kebabs or meatballs or kung pao chicken, as long as the meat is halal; your hijab can be silk or linen or viscose. At the same time, there are plenty of things that cosmopolitans will not tolerate. We will sometimes want to intervene in other places because what is going on there violates our principles so deeply. We, too, can see moral error. And when it is serious enough -- genocide is the least-controversial case -- we will not stop with conversation. Toleration has its limits.

Nor can you tell us apart by saying that the neofundamentalists believe in universal truth. Cosmopolitans believe in universal truth, too, though we are less certain that we already have all of it. It is not skepticism about the very idea of truth that guides us; it is realism about how hard the truth is to find. One tenet we hold to, however, is that every human being has obligations to every other. Everybody matters: that is our central idea. And again, it sharply limits the scope of our tolerance.

To say what, in principle, distinguishes the cosmopolitan from competing universalisms, we plainly need to go beyond talk of truth and tolerance. One distinctively cosmopolitan commitment is to pluralism. Cosmopolitans think that there are many values worth living by and that you cannot live by all of them. So we hope and expect that different people and different societies will embody different values. Another aspect of cosmopolitanism is what philosophers call fallibilism -- the sense that our knowledge is imperfect, provisional, subject to revision in the face of new evidence.

The neofundamentalist conception of a global ummah, by contrast, admits of local variations -- but only in matters that don't matter. These counter-cosmopolitans, like many Christian fundamentalists, do think that there is one right way for all human beings to live; that all the differences must be in the details. If what concerns you is global homogeneity, then this utopia, not the world that capitalism is producing, is the one you should worry about. Still, the universalisms in the name of religion are hardly the only ones that invert the cosmopolitan creed. In the name of universal humanity, you can be the kind of Marxist, like Mao or Pol Pot, who wants to eradicate all religion, just as easily as you can be the Grand Inquisitor supervising an auto-da-fé. All of these men want everyone on their side, so we can share with them the vision in their mirror. "Indeed, I'm a trustworthy adviser to you," Osama bin Laden said in a 2002 "message to the American people." "I invite you to the happiness of this world and the hereafter and to escape your dry, miserable, materialistic life that is without soul. I invite you to Islam, that calls to follow of the path of Allah alone Who has no partners, the path which calls for justice and forbids oppression and crimes." Join us, the counter-cosmopolitans say, and we will all be sisters and brothers. But each of them plans to trample on our differences -- to trample us to death, if necessary -- if we will not join them. Their motto might as well be the sardonic German saying Und willst du nicht mein Bruder sein, So schlag' ich Dir den Schädel ein. (If you don't want to be my brother, then I'll smash your skull in.)

That liberal pluralists are hostile to certain authoritarian ways of life -- that they're intolerant of radical intolerance -- is sometimes seen as kind of self-refutation. That's a mistake: you can care about individual freedom and still understand that the contours of that freedom will vary considerably from place to place. But we might as well admit that a concern for individual freedom isn't something that will appeal to every individual. In politics, including cultural politics, there are winners and losers -- which is worth remembering when we think about international human rights treaties. When we seek to embody our concern for strangers in human rights law, and when we urge our government to enforce it, we are seeking to change the world of law in every nation on the planet. We have declared slavery a violation of international law. And, in so doing, we have committed ourselves, at a minimum, to the desirability of its eradication everywhere. This is no longer controversial in the capitals of the world. No one defends enslavement. But international treaties define slavery in ways that arguably include debt bondage, and debt bondage is a significant economic institution in parts of South Asia. I hold no brief for debt bondage. Still, we shouldn't be surprised if people whose incomes and style of life depend upon it are angry.

It's the same with the international movements to promote women's equality. We know that many Islamists are deeply disturbed by the way Western men and women behave. We permit women to swim almost naked with strange men, which is our business, but it is hard to keep the news of these acts of immodesty from Muslim women and children or to protect Muslim men from the temptations they inevitably create. As the Internet extends its reach, it will get even harder, and their children, especially their girls, will be tempted to ask for these freedoms, too. Worse, they say, we are now trying to force our conception of how women and men should behave upon them. We speak of women's rights. We make treaties enshrining these rights. And then we want their governments to enforce them.

Like many people in every nation, I support those treaties; I believe that women, like men, should have the vote, should be entitled to work outside their homes, should be protected from the physical abuse of men, including their fathers, brothers and husbands. But I also know that the changes these freedoms would bring will change the balance of power between men and women in everyday life. How do I know this? Because I have lived most of my adult life in the West as it has gone through just such a transition, and I know that the process is not yet complete.