We are witnessing an alarming resurgence of a type of religious intolerance we thought the nations of the U.S. and Europe had outgrown. Not since the anti-Catholic movement of the late 19th century has the U.S. known a religious panic such as the one that is now linking Muslims to terrorism, forbidding the building of mosques in many U. S. cities and towns, and poisoning the climate of community, school and workplace relations in communities across the nation.

Particularly salient at present is the controversy over the proposed Islamic community center at Ground Zero. The proposal comes from the Cordoba Initiative, a group dedicated to world peace and to respectful interreligious dialogue. They want to build the center as a beacon of Muslim peacemaking and a symbol of a cooperative future. Nonetheless, its construction is opposed by a large majority of New Yorkers. Despite the courageous stance of Mayor Michael Bloomberg in favor of inclusion and the American values of tolerance and equal respect, many organizations have joined the denunciation--even, shockingly, the Anti-Defamation League, an organization dedicated to fighting stereotyping and persecution.

Europe, meanwhile, has similar issues to contend with, and more urgently, because European traditions have always emphasized religious homogeneity and assimilation to a greater extent than U.S. traditions. From the burqa bans proposed in France and Catalonia to regulations governing the wearing of the headscarf in schools (France, Germany) and government offices and buildings (parts of Belgium and Germany, proposals in the Netherlands), fear and suspicion of Muslims is everywhere.

It looks like intolerance is the new trend, and a more baneful trend for the world's future can hardly be imagined. How might this poisonous trend be stopped?

Fear and suspicion are powerful forces, but we have resources to combat them:

clear consistent thinking; specific political/legal principles based on equal respect for human dignity; and the sympathetic imagination.

Clear thinking is the first thing that we all urgently need. Many arguments made in these recent exchanges are inconsistent and self-serving, proposing restrictions for the newcomer group that one would not be prepared to tolerate in the case of one's own group, or, more generally, treating similar cases dissimilarly without a reason. (Do people propose to ban Christian churches on the grounds that criminals have often invoked Christianity in defending horrible crimes?) Exposing such deficiencies can be very helpful, because most people want to reason well and are embarrassed when it is shown that they are reasoning badly.

But we also need specific political and legal principles. Both the U.S. and Europe have long committed to an idea of equal human dignity, and to principles of religious liberty and toleration based upon this idea. This commitment entails that the space of religious free exercise must be ample, and that it must be equal for all, whether majority or minority. Often attaining true equality requires special "accommodation" of minority practices, because such daily matters as the choice of work days and holidays, or laws about drugs and military service, are tailored to the religious needs of the majority and are heedless of minority requirements. The tradition of thought about religious freedom that stems from the U.S. Constitution's Free Exercise Clause is a good place to begin in reflecting about what it takes for religiously heterogeneous people to live together on terms of equal respect.

Because intolerance is so often caused by fear, however, we also need to confront it on the emotional level, using everything we know about the workings of emotions such as fear, sympathy, disgust, and respect. One thing we know is that demonization of "the other" is far easier if people know nothing much about this "other," have never been encouraged to think what the world looks like from that different viewpoint. In order to move beyond a climate of fear, then, we need more than good principles: we need the cultivation of sympathy, and therefore we need approaches through education and rhetoric, not just through argument.

We'd better get to work developing and implementing these strategies, or else the world will quickly become very bleak.

Martha Nussbaum teaches law and philosophy at The University of Chicago. Among other books, she is the author of Liberty of Conscience: in Defense of America's Tradition of Religious Equality (2008), and the recent Not For Profit: Why Democracy Needs the Humanities.