Arendt's first major book was titled The Origins of Totalitarianism (1951), which traced the roots of Stalinism and Nazism in both antisemitism and imperialism. In it, Arendt argues that totalitarianism was a "novel form of government," different from other forms of tyranny in that it applied terror to subjugate mass populations rather than just political adversaries. The book was opposed by some on the Left on the grounds that it presented the two movements as equally tyrannical. She further contends that Jewry was not the operative factor in the Holocaust, but merely a convenient proxy. Totalitarianism in Germany was, in the end, about terror and consistency, not eradicating Jews only.
In what is arguably her most influential work, The Human Condition (1958), Arendt differentiates political and social concepts, labor and work, and various forms of actions; she then explores the implications of those distinctions. Her theory of political action, corresponding to the existence of a public realm, is extensively developed in this work. Arendt argues that, while human life always evolves within societies, the social-being part of human nature, political life, has been intentionally constructed by only a few of these societies as a space for individuals to achieve freedom through the construction of a common world. These conceptual categories, which attempt to bridge the gap between ontological and sociological structures, are sharply delineated. While Arendt relegates labor and work to the realm of the social, she favors the human condition of action as the political that is both existential and aesthetic.
In her reporting of the 1961 Adolf Eichmann trial for The New Yorker, which evolved into Eichmann in Jerusalem: A Report on the Banality of Evil (1963), she coined the phrase "the banality of evil" to describe the phenomenon of Eichmann. She raised the question of whether evil is radical or simply a function of thoughtlessness, a tendency of ordinary people to obey orders and conform to mass opinion without a critical evaluation of the consequences of their actions and inaction. She was sharply critical of the way the trial was conducted in Israel. She also was critical of the way that some Jewish leaders, notably M.C. Rumkowski, acted during the Holocaust. This caused a considerable controversy and even animosity toward Arendt in the Jewish community. Her friend Gershom Scholem, a major scholar of Jewish mysticism, broke off relations with her. Arendt was criticized by many Jewish public figures, who charged her with coldness and lack of sympathy for the victims of the Holocaust. Because of this lingering criticism, neither this book nor any of her other works were translated into Hebrew until 1999. This controversy was answered by Hannah Arendt in the book's Postscript.
The controversy began by calling attention to the conduct of the Jewish people during the years of the Final Solution, thus following up the question, first raised by the Israeli prosecutor, of whether the Jews could or should have defended themselves. I had dismissed that question as silly and cruel, since it testified to a fatal ignorance of the conditions at the time. It has now been discussed to exhaustion, and the most amazing conclusions have been drawn. The well-known historico-sociological construct of "ghetto mentality" has been repeatedly dragged in to explain behavior which was not at all confined to the Jewish people and which therefore cannot be explained by specifically Jewish factors. This was the unexpected conclusion certain reviewers chose to draw from the "image" of a book, created by certain interest groups, in which I allegedly had claimed that the Jews had murdered themselves.
Arendt ended the book by writing:
Just as you [Eichmann] supported and carried out a policy of not wanting to share the earth with the Jewish people and the people of a number of other nationsas though you and your superiors had any right to determine who should and who should not inhabit the worldwe find that no one, that is, no member of the human race, can be expected to want to share the earth with you. This is the reason, and the only reason, you must hang.