Heidegger embraced Nazism with apparently complete enthusiasm. He was a genius: Dr Sherratt calls him "Hitler's Superman" but asks the question whether Hitler could possibly, with his "pernicious" and ignorant views attract to his cause someone so gifted. The answer was yes, and it was Heidegger. She recounts how in 1929 Heidegger had complained about the "Jewification" of his university — the word he uses is Verjudung, one that peppers the pages of Mein Kampf. 

On May 1, 1933, three months after Hitler came to power, Heidegger had joined the Nazi party in a blaze of publicity at the University of Freiburg, where he was professor and celebrated for his work in metaphysics. He had taken the precaution beforehand of disembarrassing himself of Arendt who, being Jewish, was not an ideal bedfellow. Heidegger made a speech protesting his devotion to National Socialism, and described the urgency of the need to Nazify Germany's universities. His reward was to be made rector of Freiburg, with an inauguration ceremony that he underwent in Nazi uniform and whose programme had the words of the Horst Wessel Lied printed on its back page. He then proceeded to remove all non-Aryans from the university. With the philosopher's approval, Brownshirts toured the campus and conducted military exercises there. Heidegger was such a disaster in his new post that even his loyalty to the party and the Führer could not preserve him in it for more than a year.

Heidegger endorsed the corruption of the German legal system under the Nazis. He also supported censorship. He maintained his devotion to Hitler until 1945, which ensured he would retain his chair and continue to have his books published. 

With the fall of the Third Reich, so began Heidegger's attempts to exculpate himself. He was outraged that there was a suggestion that he should be subject to denazification hearings, "singled out for punishment and defamation before the eyes of the whole city — indeed the whole world". Despite the zeal with which he had supported the Nazi party and its doctrines, Heidegger was classed merely as a fellow traveller, given emeritus status, and allowed to continue to teach.