Arendt's subtitle famously introduced the phrase "the banality of evil," which also serves as the final words of the book. In part, at least, the phrase refers to Eichmann's deportment at the trial, displaying neither guilt nor hatred, claiming he bore no responsibility because he was simply "doing his job" ("He did his duty...; he not only obeyed orders, he also obeyed the law." p. 135).
Arendt takes Eichmann's court testimony and the historical evidence available, and makes several observations about Eichmann:
- Eichmann stated himself in court that he had always tried to abide by Immanuel Kant's categorical imperative (as discussed directly on pp. 135–137). She argues that Eichmann had essentially taken the wrong lesson from Kant: Eichmann had not recognized the "golden rule" and principle of reciprocity implicit in the categorical imperative, but had only understood the concept of one man's actions coinciding with general law. Eichmann attempted to follow the spirit of the laws he carried out, as if the legislator himself would approve. In Kant's formulation of the categorical imperative, the legislator is the moral self, and all men are legislators; in Eichmann's formulation, the legislator was Hitler. Eichmann claimed this changed when he was charged with carrying out the Final Solution, at which point Arendt claims "he had ceased to live according to Kantian principles, that he had known it, and that he had consoled himself with the thoughts that he no longer 'was master of his own deeds,' that he was unable 'to change anything'" (p. 136).
- Eichmann's inability to think for himself was exemplified by his consistent use of "stock phrases and self-invented clichés," demonstrating his unrealistic worldview and crippling lack of communication skills through reliance on "officialese" (Amtssprache) and the euphemistic Sprachregelung that made implementation of Hitler's policies "somehow palatable."
- Eichmann was a "joiner" his entire life, in that he constantly joined organizations in order to define himself, and had difficulties thinking for himself without doing so. As a youth, he belonged to the YMCA, the Wandervogel, and the Jungfrontkämpferverband. In 1933, he failed in his attempt to join the Schlaraffia (a men's organization similar to Freemasonry), at which point a family friend (and future war criminal) Ernst Kaltenbrunner encouraged him to join the SS. At the end of World War II, Eichmann found himself depressed because "it then dawned on him that thenceforward he would have to live without being a member of something or other" (pp. 32–3).
- Despite his claims, Eichmann was not, in fact, very intelligent. As Arendt details in the book's second chapter, he was unable to complete either high school or vocational training, and only found his first significant job (traveling salesman for the Vacuum Oil Company) through family connections. Arendt noted that, during both his SS career and Jerusalem trial, Eichmann tried to cover up his lack of skills and education, and even "blushed" when these facts came to light.
- Arendt confirms several points where Eichmann actually claimed he was responsible for certain atrocities, even though he lacked the power and/or expertise to take these actions. Moreover, Eichmann made these claims even though they hurt his defense, hence Arendt's remark that "Bragging was the vice that was Eichmann's undoing" (p. 46). Arendt also suggests that Eichmann may have preferred to be executed as a war criminal than live as a nobody.
- Arendt argues that Eichmann, in his peripheral role at the Wannsee Conference, witnessed the rank-and-file of the German civil service heartily endorse Reinhard Heydrich's program for the Final Solution of the Jewish question in Europe (German: die Endlösung der Judenfrage). Upon seeing members of "respectable society" endorsing mass murder, and enthusiastically participating in the planning of the solution, Eichmann felt that his moral responsibility was relaxed, as if he were "Pontius Pilate".
- During his imprisonment before his trial, the Israeli government sent no fewer than six psychologists to examine Eichmann. These psychologists found not only no trace of mental illness, but also no evidence of abnormal personality whatsoever. One doctor remarked that his overall attitude towards other people, especially his family and friends, was "highly desirable", while another remarked that the only unusual trait Eichmann displayed was being more "normal" in his habits and speech than the average person (pp. 25–6).
Arendt suggests that this most strikingly discredits the idea that the Nazi criminals were manifestly psychopathic and different from "normal" people. From this document, many concluded that situations such as the Holocaust can make even the most ordinary of people commit horrendous crimes with the proper incentives, but Arendt adamantly disagreed with this interpretation, as Eichmann was voluntarily following the Führerprinzip. Arendt insists that moral choice remains even under totalitarianism, and that this choice has political consequences even when the chooser is politically powerless:
[U]nder conditions of terror most people will comply but some people will not, just as the lesson of the countries to which the Final Solution was proposed is that "it could happen" in most places but it did not happen everywhere. Humanly speaking, no more is required, and no more can reasonably be asked, for this planet to remain a place fit for human habitation.
Arendt mentions, as a case in point, Denmark:
One is tempted to recommend the story as required reading in political science for all students who wish to learn something about the enormous power potential inherent in non-violent action and in resistance to an opponent possessing vastly superior means of violence.
It was not just that the people of Denmark refused to assist in implementing the Final Solution, as the peoples of so many other conquered nations had been persuaded to do (or had been eager to do) — but also, that when the Reich cracked down and decided to do the job itself it found that its own personnel in Denmark had been infected by this and were unable to overcome their human aversion with the appropriate ruthlessness, as their peers in more cooperative areas had.
On Eichmann's personality, Arendt concludes:
Despite all the efforts of the prosecution, everybody could see that this man was not a "monster," but it was difficult indeed not to suspect that he was a clown. And since this suspicion would have been fatal to the entire enterprise [his trial], and was also rather hard to sustain in view of the sufferings he and his like had caused to millions of people, his worst clowneries were hardly noticed and almost never reported (p. 55).
Beyond her discussion of Eichmann himself, Arendt discusses several additional aspects of the trial, its context, and the Holocaust.
- She points out that Eichmann was kidnapped by Israeli agents in Argentina and transported to Israel, an illegal act, and that he was tried in Israel even though he was not accused of committing any crimes there. "If he had not been found guilty before he appeared in Jerusalem, guilty beyond any reasonable doubt, the Israelis would never have dared, or wanted, to kidnap him in formal violation of Argentine law."
- She describes his trial as a show trial arranged and managed by Prime Minister Ben-Gurion, and says that Ben-Gurion wanted, for several political reasons, to emphasize not primarily what Eichmann had done, but what the Jews had suffered during the Holocaust. She points out that the war criminals tried at Nuremberg were "indicted for crimes against the members of various nations," without special reference to the Nazi genocide against the Jews.