"Ideology and Terror" is Hannah Arendt's attempt to determine in what sense totalitarian governments like those of Adolf Hitler and Josef Stalin are historically new. She begins by arguing that other approaches, like those of psychology and sociology, that have tackled this question before now are inadequate because they take concepts like the "individual" and "society" for granted. Totalitarianism fundamentally redefines these, and shows us that they are far from stable.

Firstly, totalitarianism has a different relationship to the law than other governments. Other governments are either lawful—they pass and uphold laws—or lawless—they simply steal from the citizenry. Totalitarianism destroys this distinction. It claims to be following a higher law, that of "History" or "Nature," that makes human laws irrelevant. Because this higher law is usually one of conflict and upheaval, the laws in totalitarian societies are constantly changing, becoming more strict and violent, with the goal of bringing about on earth the final realization of the higher law on which it draws. In this way, totalitarian societies also render individual judgment and conscience moot.

Terror—the constant warfare of the government against its citizens—is a constant of totalitarian governments because, since they destroy individual judgment, they have no way of getting individuals to participate in government. Terror forces them into a collective. Terror is also intended to combat the constant birth of new individuals, who might shake the stability of totalitarian rule. In effect, through terror, totalitarian governments try to outpace the new human beings being born to reach their desired end goal (dominance of the master race, a classless society) before these new individuals can shake their grip.

Totalitarian governments justify this terror using ideology. ideology is a form of non-thought that sees the world and everything in it as all explainable from a single idea. Because it is a logical thought that deduces everything from this first principle, it is a tool for severing the individual from reality, since ideology has an explanation for everything, even things that reality seems to contradict.

Despite all this, totalitarian governments would not be possible if they did not answer a decisive need in individuals. That need is to overcome the isolation of modern life, produced by the industrialization of labor, and the alienation and anonymity of contemporary life. By shattering the private lives of individuals and binding them by force into a collective, totalitarian governments offer a cure for the sense of utter abandonment and helplessness that modern life produces in most people. Therefore, totalitarian governments are unthinkable before the age of mass politics. That is ultimately what is decisively new about them.