It is only by the greatest good luck that we are not this month mourning dozens of victims of mass-casualty terrorism in New York, New Jersey, and Minnesota. There was no Chelsea massacre in September 2016, no St. Cloud slaughter, to join the sad toll: Orlando, June 2016; San Bernardino, December 2015; Chattanooga, July 2015; Boston, April 2013; Fort Hood, November 2009.

Perhaps because they failed to generate fear and sorrow, the Chelsea attempt and the St. Cloud attack succeeded in generating lively controversy. Chelsea, St. Cloud, Orlando, San Bernardino, Chattanooga, Fort Hood—they seem to form a pattern, but do they? And if so, a pattern of what?

That question became instantly controversial on the night of September 17. Politicians tussled over whether to call the attacks “terrorism,” and if terrorism, of what kind.

“Hillary Clinton won't even say the words ‘radical Islamic terrorism.’ She won't say the words.” That was Donald Trump’s message to supporters in Toledo, Ohio, on September 21.

Clinton had already faced—and replied to—similar criticism after the Orlando massacre.

“From my perspective,” she said, “it matters what we do more than what we say. And it mattered we got bin Laden, not what name we called him. I have clearly said we—whether you call it radical jihadism or radical Islamism, I’m happy to say either. I think they mean the same thing.”

When commentators dismiss such concerns as “mere semantics,” they mean to say: “This is a futile, pointless discussion.”

That’s a mistake. Semantics is the branch of linguistics and logic that deals with meaning. When we argue over what to call a crime like the stabbings in St. Cloud and the bombings in New York and New Jersey, we are arguing over what they mean. That’s a supremely important conversation.

Last year, a distinguished French philosopher named Pierre Manent attempted to offer an answer in a book-length essay, Beyond Radical Secularism. He began writing after the Charlie Hebdo attacks in January 2015, and published just before the atrocious mass murders of November 2015.

The book was very widely debated and discussed in France. Americans may have more trouble assimilating it, because of its very French style. Beyond Radical Secularism is a book of bold assertions and heroic generalizations. We flinch from those on the western side of the Atlantic (if I may hazard a bold assertion and heroic generalization of my own). But if we flinch in this case, we’ll miss something important—not only to our French friends and partners, but to ourselves.

Pierre Manent writes: “If, in order to analyze the same phenomenon, one person repeatedly uses the word ‘Islam,’ whereas another recommends above all that this word be avoided, it is clear that we are condemning ourselves to going around in a sterile circle, and not without the ritual exchange of offensive epithets.”

Manent is one of those who want to use the word “Islam,” not in order to blame or condemn a group of people (he very sedulously refrains from doing anything like that), but in order to identify more precisely the challenge Western societies face in consequence of the large-scale migration from Muslim-majority lands. The French version of the challenge is particularly extreme: It has entailed not only spectacular acts of terrorism, but a proliferation of lower-intensity confrontations between Muslim citizens and state authority. One view, often heard in the United States, attributes France’s difficulties with Muslim migration not to the migration, but to the society receiving the migration.

“France seems to alienate many more of its citizens and residents, well beyond those who actually join the Islamic State,” wrote the sociologist Farhad Khosrokhavar in The New York Times in July 2016. Khosrokhavar’s explanation of this alienation will sound familiar, for it is often heard in the United States:

Britain and Germany give non-local minorities ample leeway to publicly express and practice their religious and communal preferences. France insists—in the name of republicanism—that religion should remain a strictly private affair. An ideological nation par excellence, it focuses on symbolic issues like wearing headscarves or holding collective prayers in public places.

This is a reassuring message, if not for the French, then for everybody else. Avoid French mistakes, and you avoid French results. Only … other nations are experiencing French results, in lesser degrees—the United States very much included. Alongside the roster of terrorist crimes over the past decade should be considered the longer tally of failed, foiled, or botched attempts: a car bomb in Times Square, a model-aircraft bomb allegedly destined for the Pentagon, and so on. These attempts often look incompetent, even ridiculous, after they are thwarted. Unlike the terrorists of 15 years ago, the people involved in such plots in the United States operate with much less, if any, support from international networks. Yet what they do indicate is that the difference between the French and other Western countries may be explained less in terms of France’s Revolutionary tradition, much more in terms of France’s—until recently—much larger Muslim minority population (almost 8 percent). As migration has recently swelled Muslim minority populations in Sweden and Germany, they too have experienced higher levels of alienation and conflict, most notoriously the New Year’s Eve sexual assaults of December 31, 2015.

Manent wants to inscribe religious and cultural conflict into the very center of this story.

The immense majority of our Muslim fellow citizens have nothing to do with terrorism, but terrorism would not be what it is, it would not have the same reach or significance, if the terrorists did not belong to this population and were not our fellow citizens. These terrorist acts would simply be odious crimes subject to ordinary justice if they were not guided by an aim of war and by the intent to ruin the very possibility of a common life. … It is not because of a few actions by the ‘unbalanced’ that the French state has given military protection to the Jewish institutions of France, including especially Jewish schools.

Here’s what Manent sees:

The Muslim world in North Africa, the Middle East, and West Asia has entered a period of crisis and failure. Millions of people have emigrated from this world to the West. They brought their old faith, culture, and habits of life with them—and the receiving countries were too morally enfeebled to impose change upon them. Those receiving countries have lost faith in their old religions, and in their own nationhoods.

This is not a story of right and wrong, in Manent’s telling.

It would be quite inappropriate for Europeans and more generally Westerners to be scandalized, since they have for four centuries been the great expansive force in the world and have for four centuries laid down the law for the world. Human things do not stand still; they go forward or backward, either momentum is on their side or it is not. … There was an immense tide that came from Europe and covered the world, or almost. The shrinkage we are now witnessing is less spectacular, but it is much more significant because, rather than retracting or withdrawing the often-artificial or unjust extensions of its power, Europe is disarming itself at its core.

Yet if it is not a scandal, it remains a shock for Europeans, for the first time in a long time, to see their societies reshaped from outside, rather than from within. But this reshaping is not a morality tale either, from Manent’s point of view.

We did not impose conditions upon their settling here, and so they have not violated them. Having been accepted as equals, they thus have every right to think that they were accepted “as they were.” We cannot reverse this acceptance without breaking the tacit contract that has accompanied immigration over the last forty years.

That short phrase “as they were” expresses the assumption on the author’s part likely to seem most obvious  to a French reader—and most frustratingly in need of substantiation to an American reader.

Is it really true that the Muslim immigrants to Europe are not assimilating to European ways? Manent insists that they are not, not in an argumentative way, but rather in a tone that makes clear that he is saying something his audience will find obvious and uncontroversial. Americans—with their passionate conviction of the inevitability of assimilation—may wonder at Manent’s pessimistic certainty.

We may grant the diversity of individual paths and the social and moral heterogeneity that exists among French Muslims, but it remains that in our country we are we witnessing the extension and consolidation of Muslim practices rather than its shrinking or relaxation. This social fact is also the major political fact that we must take into account. To take it into account is first of all to accept the fact that on this matter we have very little power. Our Muslim fellow citizens are now too numerous, Islam has too much authority, and the Republic—or France, or Europe—too little for things to be otherwise. I therefore conclude that our regime must concede, and frankly accept their ways, since the Muslims are our fellow citizens.

Americans may likewise be jarred by Manent’s easy “us” and “them.” American public discourse often holds that “we” have no religious identity—and that “they” instantly become “us” by the act of naturalization. President Obama has boldly ventured even further, repeatedly (and anti-historically) insisting that “Islam has always been part of America.”

Manent has no patience for any of this.

Islam, as a human association and a way of life, is just as external to France’s history as Catholicism has been internal to it. … To be internal is not in itself meritorious, and to be external is no disgrace; but this difference of situation obviously has immense consequences for the social ... possibilities that are before us.

Manent stresses that he does not write as a Catholic, or even as a believer. A former student of the French sociologist Raymond Aron, he upholds France’s embattled liberal tradition. He writes generously and movingly of France’s Jewish minority, of Christian Europe’s guilt in the Holocaust, and of the meaning and importance of the state of Israel. History however remains history, and France remains “a country of Christian mark,” in the ingenious phrase of Manent’s translator, Ralph C. Hancock of Brigham Young University. Thus, while France had to emancipate itself from political Catholicism in order to become liberal, nobody ever worried about how to integrate Catholics into French society. To be French is precisely to belong to a country shaped by Catholicism and by Christianity more generally—and likewise, to belong to a country  not shaped by Islam except—until comparatively recently—as something foreign, exotic, and often dangerous.

But if Manent does not hold anyone up to blame, the results of the process he describes remain in his view highly blameworthy: an accelerating breakdown of national life, as ever-greater numbers of French citizens reject both the law of the state and the norms of society. To make a success of the migration, he argues, the law and those norms must be reimposed—and in order to be reimposed, they must adapt to new circumstances.

What would “adaptation” mean?

It probably sounds uncouth in French, but a social-science-minded American might call Manent’s solution “tragic asymmetrical multiculturalism.”

Multiculturalism: Western society should, he argues, find room for Muslim faith and cultural practices. The hijab and other religious symbols should be permitted in public and official places. Where requested, public swimming pools should set hours for single-sex swimming. Local governments should subsidize the creation of Muslim prayer spaces where they are in short supply. Manent proposes only two exceptions to the rule of accommodation: no tolerance for polygamy or for face-veiling. The latter practice, he argues, attacks the possibility of common life by cutting human beings off from interaction with follow citizens.

Asymmetrical: The quid pro quo for accommodation of the minority is the acceptance by the minority that it is a minority within a society that will continue to reject many of its core beliefs. French Muslims do not “enter into an empty space, but will have to find their place within a world that is full,” Manent writes. What France can offer is permission to “form a distinct community within a larger community that is not Muslim and that everybody knows is not Muslim.” What it cannot accept is a minority “wishing secretly to rule.” Crucial to achieving this balance is a rediscovery by non-Muslim French of their own identity and nationhood. Manent remarks how strange it is that while everybody willingly names French Muslims, there is no name for French non-Muslims. One community can be identified by what it is; the other only only as those who happen not to belong to that one identifiable community. A community defined only by what it is not, is no community at all—and certainly not a community that can successfully coexist with a sub-community strongly defined by its own obligatory rule of morals and customs.

Finally, tragic: The solution proposed by Manent is not a solution that he welcomes. On the contrary: “[W]e are forced to make concessions that we would rather not make, or to accept a transformation of our country that we would have preferred to avoid, and that even sometimes deeply saddens us.” He puts little faith in promises that Islam will modernize in ways that Westerners will find more congenial: “[W]e renounce the vain and somewhat condescending idea of an authoritarian ‘modernizing’ of their way of life.” Such talk “overestimates enormously the powers of secularism while underestimating Islam’s capacity of resistance or affirmation.”

Americans will find Manent’s analysis and prescriptions very strange, but maybe less strange than they might have in former years. Liberal-minded Americans resist interpreting men like the Chelsea bomber as religiously motivated, lest that interpretation open the door to intolerance. This resistance leads them to deny the killers’ and would-be killers’ own stated explanation for their actions. Even more ludicrously, it drives the president of this secular republic to issue pronouncements on what is and what is not truly Islamic.

Manent is writing in a French manner for French people about French problems. Americans face different problems, and they talk about them in different ways. Yet there is wisdom to be gained from Manent’s profound intelligence despite this. As one listens to the frantic circumlocutions of politicians and law-enforcement officers after incidents like those of September 17, it would be well to keep in mind this sharp and mercilessly witty observation from Paris:

We have ... borrowed from Islamic propaganda the notion of Islamophobia that now plays a major and troubling role in our social and political life. It has no meaning, but it has a function. The notion of Islamophobia makes it possible tendentiously to disqualify all speech on Islam or on the Muslims. Anyone who begins a sentence by the term “Muslims” knows that he must be careful about the words that follow, for an offense is in the making. It is possible to speak calmly of Muslims only in order to give voice to legitimate complaints that they address or could address to the rest of the social body. … We can speak of Muslims to say that they have too few mosques and of Christians to say that they have too many churches. Once the notion of Islamophobia is established and validated, it is impossible to speak of Muslims except to state their grievances, and they cannot speak except to complain.