Noah Berlatsky argues regulating hate speech would bring down Nazis and white supremacists in an article for NBC News, claiming unregulated free speech empowers bigots and punishes their targets. But he underestimates the power of free speech.

In truth, letting white nationalists speak doesn’t leave us defenseless against their ideas. It actually helps bring them down by giving people a chance to invalidate their ideas in a public space. White nationalism is a deeply emotional idea, which makes its followers susceptible to the right kinds of persuasion.

Racism has its roots in what social psychologist Jonathan Haidt calls our disgust module. According to Haidt, humans evolved a disgust module in our brains so that we wouldn’t eat poisonous foods or infected meat. But over time, our disgust module morphed, and now it’s primarily triggered by “outgroup members” such as people of a different race.

Haidt’s theory suggests that the best way to combat racism is to expose racists to the people they’re bigoted towards. If a white supremacist starts talking to a black man, after a few conversations that black man could move from “outgroup member” in the white supremacist’s mind and into “fellow human being.” Daryl Davis, a black musician, has been proving this for years. He makes a hobby of befriending KKK members and convincing them to disavow white supremacy. To date, he’s convinced more than 200 KKK members to turn in their robes, including an Imperial Wizard.

Davis’ fight against Klan ideas wouldn’t be possible if Klan members were censored. In a world where nobody is allowed to voice white nationalist sentiments, how would Davis know who to target? How would he know which Klan arguments to rebut, if those arguments couldn’t be raised in the first place?

“Give them a platform,” Davis said of his methods. “You challenge them.”

Berlatsky claims that the United States should adopt hate speech regulations like Germany and France. But censorship in these countries works better on paper than in reality. Former National Front leader Jean-Marie Le Pen was convicted under France’s over-broad anti-speech laws of trivializing the Holocaust. But his conviction hasn’t stopped him from repeating his talking points about the deaths of 6 million Jews. In spite of laws against denying the Holocaust, 11 percent Western Europeans who have heard of the Holocaust believe that it was either a myth or an exaggeration.

Censorship laws are also ineffective because it’s impossible for the government to police what every single person says or writes, especially in the age of the internet. And while laws against preaching odious ideas can deter some speakers, they can also create publicity for their views. When a Holocaust denier was brought to court in Canada in 1985, journalists covering the case had to explain his ideas and reasoning in order to inform their readers.

Censorship also makes off-limits ideas look more attractive. When we censor ideas, we’re implying to the unconverted that these ideas have merit. If the censored ideas were wrong, critics ask, wouldn’t we welcome an honest debate? We’ve already seen this dynamic play out with regard to climate change. Many liberals insist that the science is settled on climate change, and therefore we shouldn’t even be debating the subject.

As professional science explainer Bill Nye put it in an interview with Salon: “Part of the solution … is getting the deniers out of our discourse. You know, we can’t have these people — they’re absolutely toxic.”

Conservatives who deny climate change are motivated in part by this censoring impulse. In a column for The Blaze lambasting the liberal view on climate change, conservative Matt Walsh wrote, “Progressives use labels like ‘climate denier’ or ‘climate skeptic’ … because they are not interested in an honest discussion.” To Walsh, this refusal to engage in an honest discussion amounts to “religious zealotry.” He might be wrong about progressives’ intentions, but it’s not hard to see how his conception of the debate might feed into his skepticism of climate change.

Only the most die-hard environmentalists would equate climate change deniers with white nationalists, but the principle of censorship applies to both. When we try to shut down one side of the debate, all we’re doing is telling those who haven’t picked a side yet that the censored ideas are worth considering.

Repressive governments have historically stifled the rights of dissidents, because they realize their own ideas don’t hold up to criticism. But this censorship backfires. During the civil rights movement, black men and women marched to demand equal rights. Southern state and local governments tried to silence the marchers, using beatings, fire hoses, and attack dogs. America saw black men and women proudly asserting their rights, while violent governments tried to shut them down. The juxtaposition created a sea change in race relations and was a major contributor to the victory of the civil rights movement. Southern states’ attempts to squash the rights of black Americans, far from hurting the movement for equal rights, gave it a vital boost.

Free speech is already helping to win the battle against the alt-right. When university students tried to censor alt-right provocateur Milo Yiannopoulos, they merely turned him into a martyr. When Berkeley students protested his scheduled speech in February, it created a backlash and pre-orders of his book, “Dangerous,” spiked.

What brought Yiannopoulos down was not censorship, but a microphone. An interview surfaced of him defending pederasty. Immediately, prominent brands started cutting ties with the alt-right darling. Simon & Schuster canceled his upcoming book, and even Breitbart pressured him into resigning. Had he never been given a platform from which to endorse relationships with minors, he might be more popular than ever.

The free speech absolutism that Berlatsky criticizes is the key to a liberal world view. If you’re not free to speak your mind, then in what meaningful sense are you free? But free speech isn’t just a fundamental human right. It’s also our best defense against ideologies that would take away the rest of our rights.