Like many people around the world, Yale historian Timothy Snyder responded to the election of Donald Trump by fuming on social media. “Americans are no wiser than the Europeans who saw democracy yield to fascism, Nazism, or communism,” he lamented in a Facebook post on November 15. Drawing on his field of expertise—Europe in the era of Stalin and Hitler—Snyder went on to offer 20 “lessons” for how to resist a dictatorship. His post went viral, amassing more than 13,000 likes. He has now expanded that post into On Tyranny, a curious mixture of historical anecdotes and self-help bromides, premised on the idea that America is at the dawn of a tyrannical age, and that the past offers clues for resistance.

The ominous overtones of his project closely match the public mood of recent months. After Trump’s win, dystopian novels like George Orwell’s 1984 and Sinclair Lewis’s It Can’t Happen Here sprang to the top of best-seller lists, and Americans discovered a newfound interest in theorists of dictatorship and authoritarianism. Warning of NSA surveillance, Snyder reminds us that Hannah Arendt, who fled Nazi Germany, defined totalitarianism as “the erasure of the difference between private and public life.” In The New Yorker, Alex Ross argued that “the Frankfurt School knew Trump was coming.” Arendt and Theodor Adorno are now discussed not as relics of the last century and its horrors, but as seers whose works speak afresh to our moment.

ON TYRANNY: TWENTY LESSONS FROM THE TWENTIETH CENTURY by Timothy Snyder Tim Duggan Books, 128pp., $7.99

Nor is Snyder the first commentator to compare Trump’s America directly to the twentieth century’s most oppressive regimes. For months before the election, writers at Vox, The Atlantic, and Slate debated whether the president could truly be deemed a fascist. In September, New York Times book critic Michiko Kakutani reviewed a biography of Hitler, emphasizing his Trump-like qualities: Without mentioning Trump himself, she evoked a “pathetic dunderhead” of a leader with a “big mouth.”

These comparisons with history’s darkest moments are deliberately drastic; their powerful emotional resonance is called on to reflect the disturbing nature of Trump’s victory. For many, his rise defies a certain conception of Americanness: World War II and the Cold War, the two existentially threatening events of the previous century, determined the types of society America opposed and defined itself against. Only in those societies, so the thinking goes, could the abuses Trump proposes have been carried out, and only from those other societies could we learn how to resist him. This version of history assures us there is no need to look too deeply into America’s own past for the origins of an authoritarian president or his supporters. To liken Trumpism to Nazism is to lament, somewhat helplessly, that we are becoming as bad as the forces we once fought.

On Tyranny starts from a salutary impulse. Snyder is right to think that the discipline of history has special value in strengthening democracy and combating authoritarianism. Too many academic historians suffer from the vice of antiquarianism. Having a narrow focus on describing the particularity of the past, they resist linking their research to today’s most pressing issues. University-based historians, in fact, are prone to see “presentism”—the active drawing of connections between the past and present—as antithetical to true scholarship. But historical consciousness, no less than the scientific method or philosophical reasoning, is a mode of thinking with practical applications. As history involves trying to figure out the minds of those who lived in a very different time, it fosters intellectual empathy. And the forensic scrutiny that historians apply to evaluating historical documents is an invaluable skill for recognizing propaganda and “fake news.”