What if Europeans, because of their well-intended concern for maintaining the principle of tolerance, are becoming entangled in a paradox similar to the one Fish identified? What if, in other words, a too-strident insistence on tolerance can produce a less tolerant society? A balance needs to be struck, but European attempts to restrict what Europeans see as expressions of religious illiberalism — from bans on veils in French schools to permitting a schoolteacher to sue a Muslim man for failure to show her a respect equal to men — may push the weight on the scale of justice beyond the tipping point.

Just as no one can say “I am lying” while referring to him or herself in the moment of speaking without falling into a paradox, the mandate to tolerate others’ beliefs implicitly excludes the very place from which it is uttered. In essence, what liberal societies are saying is, “Tolerate others’ beliefs — except when doing so contradicts this very principle.”

In order for a liberal society to ensure that its members continue to enjoy the liberties it guarantees, this excluded place needs to be held open, to be kept formal and empty. This is precisely what the First Amendment to the United States Constitution does when it prohibits Congress from making any law “respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.” Notice that the amendment says nothing about what kind of laws Congress should make; rather it focuses on limiting the content of its legislation. The German Constitution, in contrast, which runs to over 140 articles each with multiple clauses, is essentially an exhaustive enumeration of positive rights (Austria’s is even longer).

In some cases, instead of keeping that place empty and formal, and hence subject to contestation, a society may determine its content by defining what groups, behaviors or beliefs are acceptable occupants of it. This is what is happening to Europeans as they face the challenge of assimilating a new wave of immigrants from the Middle East, many of whom are Muslim.

By keeping the excluded place of enunciation and the content of the law on the same plane, what we in fact do is surreptitiously fill that space with that content. As President Obama put it in his Cairo address of 2009, “We cannot disguise hostility towards any religion behind the pretense of liberalism.” To put it another way, we must avoid filling the open space guaranteeing tolerance with a specific image of what tolerance looks like, an image that, unsurprisingly, may have a specific national character. This is why Germans of Turkish descent or French citizens of North African descent, born in those countries and speaking no other languages than German or French, can still struggle to consider themselves German or French. In contrast, even recent immigrants to the United States commonly embrace an American identity along with that of their own ethnic and national origins.

The case of the schoolteacher embodies this subtle importation of content into the formal space of toleration. Permitting the schoolteacher to sue the father for refusing to shake hands with her reaches beyond the requirement that the Muslim father obey the law to insist that he embrace a set of values and identities even if they clash with his own. It demands in essence that he cease to be who he is and that he become instead like the other fathers in the class, who do not have religious objections to shaking hands with a female teacher.

It is a sign of a license to demonize others under the veil of a society’s commitment to tolerance, and is a harbinger, perhaps, of an electorate’s willingness to welcome into the political mainstream a candidate whose platform is built on his willful denial of their society’s dark past.

This article has been updated to reflect news developments.