According to scholars Christian Gerlach and Peter Monteath, among others, the pivotal moment for Hitler’s decision came on December 12, 1941, at a secret meeting with some 50 Nazi officials, including Joseph Goebbels (Nazi minister of propaganda) and Hans Frank (governor of occupied Poland). Though no written documents of the meeting survive, Goebbels described the meeting in his journal on December 13, 1941:
Nevertheless, some acts of rescue seem to have been unplanned, spontaneous extensions of a general habit to help the needy. Indeed, most rescuers do not appear to have thought carefully about their actions or analyzed them; instead, they viewed their assistance to Jews as a natural reaction to human suffering. Some even insisted in postwar interviews that there was nothing special about what they did to save Jewish lives. Only a small fraction of rescuers saw their saving of Jews as extraordinary. A large majority of rescuers described aiding Jews because they were in pain and in need, while just over one-quarter said that they helped because it was a Christian duty. About half saw their actions as a protest against the occupation. For some rescuers, such attitudes required protecting even people they disliked.
Though it had ancient roots, Nazi ideology was far from a primitive, medieval throwback - it was capable of appealing to intelligent and sophisticated people. Many high-ranking Nazis had doctoral degrees and early supporters included such eminent people as philosopher Martin Heidegger, theologian Martin Niemoeller, and commander-in-chief of German forces in the First World War, General Erich Ludendorff. Hitler appealed with a powerful vision of a strong, united and 'racially' pure Germany, bolstered by pseudo-scientific ideas that were popular at the time.
In the 1960s, Otto Frank recalled his feelings when reading the diary for the first time, "For me, it was a revelation. There, was revealed a completely different Anne to the child that I had lost. I had no idea of the depths of her thoughts and feelings."[23] Michael Berenbaum, former director of the United States Holocaust Memorial Museum, wrote, "Precocious in style and insight, it traces her emotional growth amid adversity. In it, she wrote, 'In spite of everything, I still believe that people are really good at heart.'"[23]
Amit withstood pressure from many members of his staff who were Holocaust survivors or relatives of victims. But others thought he was right. Rafi Eitan, an Israel-born Mossad operative who led the team that caught Eichmann, told me: “Because of the need for foreign-language speakers, many of the Mossad’s recruits were from Europe, and therefore had gone through the Holocaust or lost their families in it. One can definitely understand their need for vengeance. However, there was huge pressure to deal with current requirements, and with the resources being as meager as they were, in no way would it have been right to give the Nazi matter priority.”
From 1933 onward, anti-Jewish propaganda had flooded Germany. Under the skillful direction of Joseph Goebbels, his Nazi Propaganda Ministry churned out a ceaseless stream of leaflets, posters, newspaper articles, cartoons, newsreels, slides, movies, speeches, records, exhibits and radio pronouncements. As a result, the accusations, denunciations and opinions which Hitler first expressed in his book, Mein Kampf, had become institutionalized, accepted as time-tested beliefs by all Nazis, taught as fact to impressionable youths, and drilled into the minds of eager-to-please SS recruits.

Eva Fogelman, Conscience and Courage: Rescuers of Jews during the Holocaust (New York, 1994); Philip Friedman, Their Brothers’ Keepers (New York, 1957); Martin Gilbert, The Righteous: The Unsung Heroes of the Holocaust (New York, 2003); Philip Paul Hallie, Lest Innocent Blood Be Shed: The Story of the Village of Le Chambon, and How Goodness Happened There (New York, 1979); Samuel Oliner and Pearl Oliner, The Altruistic Personality: Rescuers of Jews in Nazi Europe (New York, 1988); Mordecai Paldiel, The Path of the Righteous: Gentile Rescuers of Jews during the Holocaust (Hoboken, N.J., 1993); Michael Phayer and Eva Fleischner, Cries in the Night: Women Who Challenged the Holocaust (Kansas City, Mo., 1997); Nechama Tec, When Light Pierced the Darkness: Christian Rescue of Jews in Nazi-Occupied Poland (New York, 1986); Nechama Tec, In the Lion’s Den: The Life of Oswald Rufeisen (New York, 1990); Nechama Tec, Defiance: The Bielski Partisans (New York, 1993).

In early 1943, encouraged by von Verschuer, Mengele applied to transfer to the concentration camp service.[20][30] His application was accepted and he was posted to Auschwitz, where he was appointed by SS-Standortarzt Eduard Wirths, chief medical officer at Auschwitz, to the position of chief physician of the Zigeunerfamilienlager (Romani family camp) at Birkenau,[20][30] a subcamp located on the main Auschwitz complex. The SS doctors did not administer treatment to the Auschwitz inmates, but supervised the activities of inmate doctors who had been forced to work in the camp medical service.[31] As part of his duties, Mengele made weekly visits to the hospital barracks and ordered any prisoners who had not recovered after two weeks in bed to be sent to the gas chambers.[32]
The Nazis used the phrase Lebensunwertes Leben (life unworthy of life) in reference to the disabled and mentally ill.[92] On 14 July 1933, the Law for the Prevention of Hereditarily Diseased Offspring (Gesetz zur Verhütung erbkranken Nachwuchses), the Sterilization Law, was passed, allowing for compulsory sterilization.[93][94] The New York Times reported on 21 December that year: "400,000 Germans to be sterilized".[95] There were 84,525 applications from doctors in the first year. The courts reached a decision in 64,499 of those cases; 56,244 were in favor of sterilization.[96] Estimates for the number of involuntary sterilizations during the whole of the Third Reich range from 300,000 to 400,000.[97]
Perhaps the main area of dispute about this process concerns Hitler’s precise role in ordering the killing of the Jews. Remarkably, we simply do not know, in an unequivocal way, what Hitler’s precise role was. The dictator often gave oral orders to senior henchmen such as Heinrich Himmler that were never written down, and historians can only infer Hitler’s precise role and intentions from evidence which is infuriatingly inadequate and contradictory. Because of the lack of unambiguous evidence, historians have been divided for decades, rather misleadingly, into so-called “intentionalists,” who argue that Hitler always intended to kill the Jews, and “functionalists,” who claim that the killing process somehow, as it were, welled up from local SS units in Russia until it became general Nazi policy.

Mengele's work also involved carrying out selections, a task that he chose to perform even when he was not assigned to do so, in the hope of finding subjects for his experiments,[33] with a particular interest in locating sets of twins.[34] In contrast to most of the other SS doctors, who viewed selections as one of their most stressful and unpleasant duties, he undertook the task with a flamboyant air, often smiling or whistling a tune.[35][31] He was also one of the SS doctors responsible for supervising the administration of Zyklon B, the cyanide-based pesticide that was used for the mass killings in the Birkenau gas chambers. He served in this capacity at the gas chambers located in crematoria IV and V.[36]