AT A National Prayer Breakfast last Thursday, Barack Obama made the point that Islam is hardly the first religion to be hijacked and perverted by murderous extremists. Indeed, groups have been distorting religious faith for nihilistic ends for centuries. By way of example, he mentioned the atrocities committed by Christian Crusaders in the name of God. This reference to Christianity, historically accurate though it was, earned him quite a bit of criticism, mostly from Republicans (as we covered on our Erasmus blog). What has received less attention, however, is the way Mr Obama went on to call for Americans to refrain from insulting the faith of others. It was an odd statement. He began by praising the wisdom of America’s founding fathers for their sophisticated understanding of the relationship between freedom of speech and freedom of religion. (“For to infringe on one right under the pretext of protecting another is a betrayal of both.”) “But,” he continued—and it was a big “but”—in “modern, complicated, diverse societies”, Americans must “exercise civility and restraint and judgment.” The president didn’t exactly deny the right to free expression. His message was more along the lines of, just because you can say something doesn’t mean you should.

But that’s not quite how freedom of expression works. Exercising judgment over what one says or does makes some common sense, but this is a matter of personal desire, not public command. Rights are not about civility or manners or being sensitive; they’re about unbending individual freedoms. What is the worth of a right if people feel obliged (or subtly compelled) to not exercise it in practice? It’s disturbing, only a month after the Charlie Hebdo massacre, to hear the leader of the free world advocate what is essentially a kind of self-censorship. Yet Mr Obama’s statements reflect an increasingly popular sentiment: that diversity of culture, instead of increasing diversity of expression, should actually constrain it. The objective, it would seem, is not to become more tolerant of opposing ideas but more wary about how we discuss them.

Another term for this might be "political correctness". As Jonathan Chait recently outlined in New York magazine, political correctness is a style of politics, generally wielded by leftists, that attempts to regulate public discourse by defining opposing views as bigoted and illegitimate. “P.C.” disciples make it their business to call out perceived racial, religious and gender biases in the service of forging a more equal society. A central tenet of the P.C. movement, Mr Chait notes, is that people should be expected to treat faintly unpleasant ideas as full-scale offenses; that the threat to civil society isn’t angry mobs out to crush opposing ideas but rather the ideas themselves. This is the “Je Ne Suis Pas Charlie” crowd—those who accused the newspaper of racism (though it satirised all races and religions) and deemed the cartoons hate speech.

It wasn’t wrong for people to criticise Charlie Hebdo. These critics have the same right to free expression as the cartoonists. But it is wrong if those criticisms lead to calls for censorship. Indeed, this was the force of their argument: that Charlie Hebdo shouldn’t have published those cartoons, and that the journalists, in some sense, got what was coming to them.

In this way, the P.C. movement is essentially a programme of censorship. It undermines a fundamental democratic right to free expression—a right that should extend to everyone, regardless of how contentious, bigoted or prejudiced these views might be—in order to advance a perception of decency and social harmony. But is it really harmony we win when we back down from satirising religious radicals? Or when we attack people for wishing “Merry Christmas” instead of “Happy Holidays”? This seems more like a way to cultivate social anxieties; a fear of forgetting the proper code words. Flemming Rose, editor of the Danish paper that published the controversial Mohammed cartoons in 2005, calls this approach a “tyranny of silence.”

The rise of various outlets for speech, and the explosion of social media, has been accompanied by a similarly steep rise in P.C. police officers. Legions of commentators, armed with hashtags and memes, now eagerly ferret out all evidence of racism and sexism in our speech. At the University of California in Los Angeles, for example, students protested when a professor corrected a student’s spelling of the word "indigenous" by replacing an upper-case I with a lower-case one. This correction was a "linguistic micro-aggression", according to the students—“a perceived grammatical choice that in actuality reflects ideologies”—who staged a sit-in to make their case.

The desire to create a more egalitarian society through a kind of hyper-conscious semantic regulation is in some ways understandable. In a world full of prejudice and discrimination, calling attention to perceived errors of judgment can be a way of combating them. But there is something deadening about a society that insists on a certain uniformity of speech. And by creating an invisible fence of anxiety around language, the P.C. movement effectively curbs people’s freedom to speak their mind without necessarily securing any new rights. As Mr Chait writes, “political correctness is not a rigorous commitment to social equality so much as a system of left-wing ideological repression. Not only is it not a form of liberalism; it is antithetical to liberalism… It is an undemocratic creed.”

On the surface, President Obama’s call to respect other religions seems sensible. It’s tempting to think there would be less violence in the world if everyone refrained from insulting everyone else. But criticism—even misguided, prejudiced criticism—is a necessary ingredient of debate and deliberation. We only have to remember what medieval Europe looked like in the grip of the Catholic Church or what many countries with blasphemy laws look like today. The future of democracy in a multicultural society depends not on the seemingly benign suppression of insensitive speech but on its uncompromising protection.