The jolting arrival of the post-truth era in American politics has sent George Orwell’s 1984 zooming to the top of Amazon’s bestseller list. But for a deeper understanding of the threat fake news and “alternative facts” pose for us, it’s not Orwell’s dystopian novel that we should be reading; it’s political philosopher Hannah Arendt’s Vietnam War-era essay “Truth and Politics,” which marks its 50th anniversary this month.

Arendt was born in Germany, fled the Nazis, and rose to prominence in 1951 with her three-volume history, The Origins of Totalitarianism. In “Truth and Politics,” she provides an analysis of political lying that speaks to an America as divided today as it was in the ’60s by the Vietnam War.

“Truth and Politics” appeared in the Feb. 25, 1967 New Yorker at a time when Arendt was still being criticized for her controversial Eichmann in Jerusalem: A Report on the Banality of Evil. Along with a companion essay, “Lying in Politics,” which Arendt published in 1971, “Truth and Politics” puts into historical perspective the internal dangers to the body politic that come when political leaders engage in the mass manipulation of facts.

Instead of Orwell’s Ministry of Truth, Arendt provides her readers with a lesson in how “defactualized” thinking becomes normalized. In her concern with the process by which the dividing lines between actual facts, invented facts, and opinion get blurred, Arendt draws on the ideas of founding father James Madison, who in his famous essay 49 in the Federalist Papers observed that “all governments rests on opinion” but worried over the threat posed to a young democracy by manipulated opinion.

Early in “Truth and Politics,” Arendt makes clear that she is not talking about an idealized version of politics. “No one has ever doubted that truth and politics are on rather bad terms with each other,” she sardonically notes. She then goes on to say that lies told to deceive the enemy in wartime or to keep secrets from the public are not her concern when it comes to the relationship between truth and politics.

It is organized lying, designed to sway how voters think, that Arendt believes is the great political threat to democracy. Combatting mass falsehoods is always an uphill battle, she warns. Here her argument echoes the line that Jack Nicholson popularized in A Few Good Men, the 1992 film in which as a Marine Corps colonel on trial, he shouts at the lawyer questioning his judgment, “You can’t handle the truth.”

Arendt believes that political liars take advantage of supporters who don’t want to deal with the truth in the form of unwelcome facts, and as a result, political liars have a decided, initial advantage over truth tellers. Political liars can tailor their facts to fit the hopes of their audience and, by doing so, have plausibility on their side. The false facts that are liars’ stock and trade are what those listening to them want to believe.

But as far as Arendt is concerned, when liars prevail, it is not merely that falsehood wins out over truth. The whole political system is turned on its head: fact and opinion become interchangeable.

The first loss caused by political lying, Arendt points out, is, ironically, in the value of opinion. Freedom of opinion is a “farce,” she contends, unless it comes with factual information. “Facts and opinions, though they must be kept apart, are not antagonistic to each other; they belong to the same realm,” she writes. “Facts inform opinions.”

But the second loss caused by political lying is the most dangerous of all in Arendt’s judgment. It is the loss of the desire to establish the truth. When lying becomes epidemic, what follows, she contends, is “a peculiar kind of cynicism—an absolute refusal to believe in the truth of anything, no matter how well this truth may be established.” The result is that the sense by which citizens take their political bearings in the world is destroyed.

The good news, Arendt points out, is that it is difficult to reach this level of cynicism. Liars can get away with single falsehoods, even multiple falsehoods for a while, but there is a point at which lies become counterproductive. When those who are lied to find that their lives are made worse by the lies, they come to disbelieve the lies.

For Arendt, it’s crucial to avoid reaching this extreme point. In the case of Vietnam, she believed at the time that the press played a crucial role in exposing the government’s lies about the success of the war, and at the end of “Lying in Politics,” she emphasizes the importance of what is crucial today—a “press that is free and not corrupt.”

That a half century after the Vietnam War, the press should again be under attack from another president and his administration makes this turn of events a welcome historical parallel. For Arendt, there is nothing banal about defending the truth when it is under siege. She is lyrical on that subject, observing in her conclusion to “Truth and Politics”: “Conceptually, we may call truth what we cannot change; metaphorically, it is the ground on which we stand and the sky that stretches above us.”

Nicolaus Mills chairs the literature department at Sarah Lawrence College. He is author of Winning the Peace: The Marshall Plan and America’s Coming of Age as a Superpower.