What are the limits of freedom of speech? It is a pressing question at a moment when conspiracy theories help to fuel fascist politics around the world. Shouldn’t liberal democracy promote a full airing of all possibilities, even false and bizarre ones, because the truth will eventually prevail?

Perhaps philosophy’s most famous defense of the freedom of speech was articulated by John Stuart Mill, who defended the ideal in his 1859 work, On Liberty. In chapter 2, “Of the Liberty of Thought and Discussion,” Mill argues that silencing any opinion is wrong, even if the opinion is false, because knowledge arises only from the “collision [of truth] with error.” In other words, true belief becomes knowledge only by emerging victorious from the din of argument and discussion, which must occur either with actual opponents or through internal dialogue. Without this process, even true belief remains mere “prejudice.” We must allow all speech, even defense of false claims and conspiracy theories, because it is only then that we have a chance of achieving knowledge.

Should liberal democracy promote a full airing of all possibilities, even false and bizarre ones, because the truth will eventually prevail?

Rightly or wrongly, many associate Mill’s On Liberty with the motif of a “marketplace of ideas,” a realm that, if left to operate on its own, will drive out prejudice and falsehood and produce knowledge. But this notion, like that of a free market generally, is predicated on a utopian conception of consumers. In the case of the metaphor of the marketplace of ideas, the utopian assumption is that conversation works by exchange of reasons: one party offers its reasons, which are then countered by the reasons of an opponent, until the truth ultimately emerges.

But conversation is not just used to communicate information. It is also used to shut out perspectives, raise fears, and heighten prejudice. Remarking on the changes wrought by fascist politics on the German language, the philosopher Ernst Cassirer wrote in 1946:

If we study our modern political myths and the use that has been made of them we find in them, to our great surprise, not only a transvaluation of all our ethical values but also a transformation of human speech. . . . New words have been coined, and even the old ones are used in a new sense; they have undergone a deep change of meaning. This change of meaning depends upon the fact that these words which formerly were used in a descriptive, logical, or semantic sense are now used as magic words that are destined to produce certain effects and to stir up certain emotions. Our ordinary words are charged with meanings; but these new-fangled words are charged with feelings and violent passions.

The argument for the marketplace of ideas presupposes that words are used only in their “descriptive, logical, or semantic sense.” But in politics, and most vividly in fascist politics, language is not used simply, or even chiefly, to convey information but to elicit emotion.

The argument from the “marketplace of ideas” model for free speech thus works only if society’s underlying disposition is to accept the force of reason over the power of irrational resentments and prejudice. Language becomes a vehicle for emotion rather than meaning. If the society is divided, however, then a demagogic politician can exploit the division by using language to sow fear, accentuate prejudice, and call for revenge against members of hated groups. Attempting to counter such rhetoric with reason is akin to using a pamphlet against a pistol.

Mill seems to think that knowledge, and only knowledge, emerges from arguments between dedicated opponents. Mill would surely then be pleased with the Russian television network RT, whose motto is “Question More.” If Mill is correct, RT, which features voices from across the broadest possible political spectrum, from neo-Nazis to far leftists, should be the paradigm source of knowledge production. However, RT’s strategy was not devised to produce knowledge. It was rather devised as a propaganda technique, to undermine trust in basic democratic institutions. Objective truth is drowned out in the resulting cacophony of voices. The effect of RT, as well as the myriad conspiracy-theory-producing websites across the world, including in the United States, has been to destabilize the kind of shared reality that is in fact required for democratic contestation.

What did Mill get wrong here?

Disagreement requires a shared set of presuppositions about the world. Even dueling requires agreement about the rules. You and I might disagree about whether President Obama’s healthcare plan was good policy. But if you suspect that Obama was an undercover Muslim spy seeking to destroy the United States, and I do not, our discussion will not be productive. We will not be talking about the costs and benefits of Obama’s health policy, but rather about whether any of his policies mask a devious antidemocratic agenda.

Far from resulting in a process that is conducive to knowledge, giving serious consideration to every opinion destroys its very possibility.

In devising the strategy for RT, Russian propagandists, or “political technologists,” realized that with a cacophony of opinions and outlandish possibilities, one could undermine the basic background set of presuppositions about the world that allows for productive inquiry. One can hardly have reasoned discussion about climate policy when one suspects that the scientists who tell us about climate change have a secret pro-homosexual agenda (as the evangelical media leader Tony Perkins suggested on an October 29, 2014, edition of his radio program Washington Watch). Allowing every opinion into the public sphere and giving it serious time for consideration, far from resulting in a process that is conducive to knowledge formation via deliberation, destroys its very possibility. Responsible media in a liberal democracy must, in the face of this threat, try to report the truth, and resist the temptation to report on every possible theory, no matter how fantastical, just because someone, somewhere, advances it.

The RT model is dangerous because it allows conspiracy theories to have a platform on par with reasonable, fact-based positions. When conspiracy theories become the coin of politics citizens no longer have a common reality that can serve as background for democratic deliberation. In such a situation, citizens have no choice but to look for markers to follow other than truth or reliability; as we see across the world, they look to politics for tribal identifications, for addressing personal grievances, and for entertainment. When news becomes sports, the strongman achieves a certain measure of popularity. Fascist politics transforms the news from a conduit of information and reasoned debate into a spectacle with the strongman as the star.

Fascist politics seeks to undermine trust in the press and universities. But the information sphere of a healthy democratic society does not include just democratic institutions. Spreading general suspicion and doubt undermines the bonds of mutual respect between fellow citizens, leaving them with deep wells of mistrust not just toward institutions but also toward one another. Fascist politics seeks to destroy the relations of mutual respect between citizens that are the foundation of a healthy liberal democracy, replacing them ultimately with trust in one figure alone, the leader. When fascist politics is at its most successful, the leader is regarded by the followers as singularly trustworthy.

In the 2016 U.S. presidential election, Donald Trump repeatedly and openly lied, openly flouting long-sacrosanct liberal norms. The U.S. mainstream media dutifully reported his many lies. Hillary Clinton followed liberal norms of equal respect; her one violation, when she called some of the supporters of her opponent “deplorables,” was endlessly thrown back in her face. And yet again and again, Americans found Trump to be the more authentic candidate. By giving voice to shocking sentiments that were presumed to be unsuitable for public discourse, Trump was taken to be speaking his mind. This is how, by exhibiting classic demagogic behavior, a politician can come to be seen as the more authentic candidate, even when he is manifestly dishonest.

The possibility of this kind of politics arises under certain conditions in a democracy. In another kind of propagandistic twisted meaning, politicians can convey the message that they are the representative of the common good by explicitly attacking the common good. To see how this perplexing situation is possible, one can look at how in the U.S. political system these conditions have arisen in the recent past.

In Federalist Paper No. 10, James Madison argued that the United States had to take the form of a representative democracy and seek to elect leaders who best represented the values of democracy. An election campaign is supposed to present candidates seeking to show that they have the common interests of all citizens at heart. Two factors have eroded the protections that representative democracy is supposed to provide.

First, candidates must raise huge sums to run for office (ever more so since the 2010 Citizens United decision by the U.S. Supreme Court). As a result, they represent the interests of their large donors. However, because it is a democracy, they must also try to make the case that they represent the common interest. They must pretend that the best interests of the multinational corporations that fund their campaigns are also the common interest.

Fascist politics seeks to destroy the relations of mutual respect between citizens that are the foundation of a healthy liberal democracy.

Second, some voters do not share democratic values, and politicians must appeal to them as well. When large inequalities exist, the problem is aggravated. Some voters are simply more attracted to a system that favors their own particular religion, race, or gender. The resentment that flows from unmet expectations can be redirected against minority groups seen as not sharing dominant traditions; goods that go to them are represented by demagogic politicians, in a zero-sum way, as taking goods away from majority groups. Some voters see such groups, rather than the behavior of economic elites, as responsible for their unmet expectations. Candidates must attract these voters while appearing not to flout democratic values. As a result, many politicians use coded language to exploit resentment, as in the Republican Party’s “Southern strategy,” in order to avoid the charge of excluding the perspectives of opposing groups. In a 1981 interview with political scientist Alexander Lamis, the infamous Republican political strategist Lee Atwater, then a consultant in Reagan’s White House (later the campaign manager for George H. W. Bush’s ’88 win), explained that racist intent had to be made less overt over time:

By 1968 you can’t say ‘nigger’—that hurts you, back-fires. So you say stuff like, uh, forced busing, states’ rights, and all that stuff, and you’re getting so abstract. Now, you’re talking about cutting taxes, and all these things you’re talking about are totally economic things and a byproduct of them is, blacks get hurt worse than whites.

Tactics like these are not a secret, and for these reasons, U.S. politics has appeared insincere to many voters. And they are sick of it—they crave principled, honest politicians. They want politicians to tell it like it is. And they will seek such candidates even in the absence of a clear set of values they share.

But how can politicians signal that they are not hypocritical, especially when voters have grown accustomed to what seems, for both real and contrived reasons, to be a deep stratum of hypocrisy?

One way for candidates to address the widespread disgust with hypocrisy is to represent themselves as champions of democratic values. In a democratic culture, such candidates would theoretically be the most attractive. However, this is not a promising strategy in certain political climates. It is difficult to represent oneself as genuinely representing the common interest in an environment of general distrust. It does not appeal to voters who reject democratic values, such as racial or gender equality, or those who simply deny that inequalities exist. And there will be fierce competition for voters who support democratic values between candidates representing themselves as their champions.

But there is a way a politician could appear to be sincere without having to vie against other candidates pursuing the same strategy: by standing for division and conflict without apology. Such a candidate might openly side with Christians over Muslims and atheists, or native-born Americans over immigrants, or whites over blacks, or the rich over the poor. They might openly and brazenly lie. In short, one could signal authenticity by openly and explicitly rejecting what are presumed to be sacrosanct political values.

The news has been transformed from a conduit of information and reasoned debate into a spectacle with the strongman as the star.

Such politicians would seem to be a breath of fresh air in a political culture that seems dominated by real and imagined hypocrisy. They would be especially compelling if they demonstrated their supposed authenticity by explicitly targeting groups that are disliked by the voters they seek to attract. Such open rejection of democratic values would be taken as political bravery, as a signal of authenticity. It was not without justification that Plato saw in democracy’s freedoms an allowance for the rise of a skilled demagogue who would take advantage of these freedoms to tear reality asunder, offering himself or herself as a substitute.

Trump is correct that our public square has been corrupted. The flow of money to candidates and attendant hypocrisy is a problem; it has led to a manifest yearning for an authentic figure who can stand up to such influences. This desire for a more honest politics cannot, however, be met by a figure whose main claim to authenticity is open disdain for truth and equal respect. Such politics only serves the purpose of further entrenching the cynicism that led us to this point, to the continued advantage of demagogues.

This essay is adapted from HOW FASCISM WORKS by Jason Stanley. Copyright © 2018 by Jason Stanley. Published by Random House, an imprint and division of Penguin Random House LLC. All Rights Reserved.