Arendt's landmark study works in three parts—antisemitism, imperialism, and totalitarianism—tracing how nineteenth-century currents fed into the Nazi and Stalinist regimes, which she treats as a genuinely new form of government distinct from ordinary tyranny or dictatorship.
Her most enduring insight concerns people rather than institutions. Totalitarian movements, she argues, feed on atomized, isolated "masses"—individuals stripped of stable class, community, and a shared world—whose loneliness makes them crave the total explanation and sense of belonging that a movement supplies.
She shows how such regimes rely on ideology (a single idea claiming to explain all of history), on terror, and on the deliberate blurring of fact and fiction, until people lose the capacity to tell true from false and become able to believe everything and nothing at once.
Difficult and dense, it remains the sharpest account of how the ground is prepared in a society long before the regime arrives—why the conditions for total rule form in people's lived experience before they ever take institutional shape.
The ideal subject of totalitarian rule is not the convinced Nazi or the convinced Communist, but people for whom the distinction between fact and fiction (i.e., the reality of experience) and the distinction between true and false (i.e., the standards of thought) no longer exist.— The Origins of Totalitarianism