The two lecture courses collected in the volume entitled Being and Truth were delivered during Heidegger's tenure as the first Nazi rector of the University of Freiburg and thus in his darkest hour as a philosopher. The lecture course The Fundamental Question of Philosophy was held in the Summer Semester of 1933. It is devoted to an exploration of the fundamental question of philosophy and its difference from what Heidegger calls the guiding question of philosophy, understood (and deconstructed) as the question concerning the beingness of beings. Its short, incomplete and largely programmatic state is most certainly due to Heidegger's responsibilities and duties as rector, which, according to the editor, must have forced him to cancel a number of lectures (it is unclear when the lectures began and ended).
The second lecture course, entitled On the Essence of Truth, ran between 7 November 1933 and 27 February 1934. Based on a thorough transcript by Wilhelm Hallwachs, it consists of a detailed exploration of the essence of truth (and untruth) and its connection with the question of Being. Yet, apart from its long introduction and numerous remarks regarding the historical and political situation of Germany, it repeats a lecture course of the same name from the Winter Semester of 1931-32 (GA 34). As such, the volume's originality and importance lie not so much in its often sketchy or repetitive philosophical content as in the manner in which it relates that content to the historical and political situation facing Germany at the time. In that respect, it supplements Heidegger's already published political texts from 1933-34, including his rectoral address of 1 May, 1933. Given the politically sensitive nature of those lectures and the room for possible mistranslations, I found the translation mostly accurate and reliable. . . .