This contribution discusses the philosophical meaning of Martin Heidegger’s Rectoral address. Firstly, Heidegger’s philosophical basic experience (Grunderfahrung) is sketched as providing the background of his Rectoral address: the being-historical concept of beginning (Anfang). Next, the philosophical question of the Rectoral address is discussed. It is shown that Die Selbstbehauptung der deutschen Universität is inquiring into the identity of human being (Dasein) in connection with the question about das Eigene (the Germans) and das Fremde (the Greeks). This opposition structures the confrontation with the beginning of philosophical thinking in the Rectoral address. When read against the philosophical background sustaining the Rectoral address, words that appear in it, such as "Kampf," "Macht," "Volk," and "Marsch" have nothing in common with the same words as used by the Nazis. It is shown that the Rectoral address is an extremely ambiguous text, because it claims a transformation of human Dasein. Although Heidegger’s view on National Socialism is distinguished from Nazi ideology, it is clear that he made a mistake about Hitler. The article explores how Heidegger later changed his mind and vocabulary, and in what way this kind of mistakes and changes of mind are inherent to philosophical empiricism.