With legislatures throughout Europe roiled by calls to outlaw burkas in public, philosopher Martha Nussbaum, usually an outspoken Europhile, finds herself at odds with popular European attitudes toward religion. Everyday religious practices, from dress to diet, Nussbaum says, reflect the search for ultimate meaning. And so the talk of banning burkas—a garment worn by some Muslim women to cover their bodies and faces—represents something more insidious than an aversion to social change: it is a denial of Muslims’ fundamental human dignity.

Nussbaum’s belief that religious liberty, especially for Muslims, is in crisis in the Western world led to a book, The New Religious Intolerance: Overcoming the Politics of Fear in an Anxious Age (Belknap Press of Harvard University Press, 2012). It offers a protest against  revanchist anti-Muslim trends in Europe and the United States. Nussbaum teaches in the Law School, the Divinity School, and  the classics, philosophy, and political-science departments, and in The New Religious Intolerance, she uses legal, philosophical, and literary analysis to identify the roots of religious prejudice and suggest ways of overcoming it.

In protecting religious minorities, Europe has seen more setbacks than the United States, Nussbaum says. Partly that’s because support for measures like the burka ban cuts across political divides, as secularists on the left find common cause with religious nationalists on the right. This convergence, along with widespread fear of Islamic terrorism, has provoked a dangerous atmosphere of intolerance, Nussbaum argues, leading not only to burka bans in France and Belgium but also to incidents of extreme violence. In 2011 Norwegian fanatic Anders Behring Breivik killed 77 people in Oslo while condemning multiculturalism and what he called the Islamization of Europe.

There are troubling instances of anti-Muslim hatred in this country—Nussbaum notes attempts to ban Sharia law in several states and the controversy over plans to build an Islamic cultural center in lower Manhattan­—but fewer than in Europe. Nothing  here, she writes, “even remotely approaches the nationwide and regional bans on Islamic dress in Europe, or the nationwide Swiss minaret referendum.” The majority of Americans believe that Muslims and other religious minorities should be allowed to practice their faith. Her book emphasizes that even many critics of the Manhattan Islamic center, Park51, acknowledged the developers’ constitutional right to build on private property.

This points to one key difference between this country and Europe: the United States has a strong legal tradition of protecting religious belief and practice; Europe “hasn’t formalized those principles,” says Nussbaum. The United States has no established church; much of Europe does. As a result, state-sponsored religious discrimination has been less frequent here, and disparate spiritual sects have flourished, making this country one of the most religious in the world.

In part, cultural history has shaped US law. Many original settlers, says Nussbaum, were “minorities and weirdos” who “got the idea that religiously diverse people have to live together.” One hero of her book is Roger Williams, Rhode Island’s founder, who envisioned the colony as a haven for those escaping religious persecution. Nussbaum finds deep contemporary relevance in his 17th-century writings. Williams believed, she says, in the “idea that conscience is sacred and that each individual has to be protected in that search.”

He promoted an approach that allowed religious minorities certain legal exceptions on the basis of their beliefs. At the same time, Williams created a model for what Nussbaum calls “civic friendship.” He wrote about his “constant zealous desire to dive into the native languages” and published a phrase book on the language of the Narragansett Indians, and he urged other Englishmen to treat native tribes with openness and respect. Despite his distaste for their spiritual practices, Williams’s writings on the Narragansett reflected what Nussbaum calls a “sympathetic imagination” that allowed him to see Native Americans as equally human to Christian settlers.

The sympathetic imagination is constantly under threat—here as well as in Europe, Nussbaum says. Throughout American history, principles of liberty of conscience have clashed with popular bigotry against religious minorities such as Catholics, Jews, and Mormons. And while the United States touts a national narrative of inclusion and diversity, that self-image is undermined by anti-Muslim fear. For Nussbaum, the furor over Park51, attempts to ban Sharia law, and other recent moves to restrict Muslim practice reveal that the social foundations of religious freedom are fragile.

The culture of empathy that thinkers like Williams advocated must be perpetually nourished, Nussbaum argues, by exposure to the broad sweep of human experience. Liberal education, she says, remains the most effective way to do this. But recent cuts to humanities funding in both secondary and higher education worry her. American students, she says, are now less likely to read the kinds of texts that help cultivate compassion for people outside one’s social group.