"When, in the summer of 1953, that is, still during my university studies in Bonn, I read a recently published lecture by Heidegger from the year 1935, the Introduction to Metaphysics, the jargon, the choice of terminology and the style told me at once that the spirit of fascism was manifested in these motives, thoughts and phrases. The book really unsettled me because I had regarded myself up till then as a student of Heidegger. The newspaper article, in which I poured out my great political and philosophical disappointment the same weekend, is therefore entitled: “Thinking with Heidegger against Heidegger”. At the time it was impossible to know that Heidegger had written anti-Semitic letters to his wife as early as 1916 and that he had become a convinced Nazi long before 1933. The fact that he had remained an unrepentant Nazi, however, could be known by 1953 at the latest."