The complete edition Vol. 2 Lectures Vol. 55. Heraclitus by Martin Heidegger offers an in-depth analysis of Heraclitus' philosophy and its significance for Western metaphysics. The two lectures, delivered in the summer semesters of 1943 and 1944, provide a comprehensive foundation for Heidegger's own writings on Heraclitus. In the first lecture, the origin of Western metaphysics is explored through the 'beginning', addressing the essence of thinking and what is to be thought initially. The second lecture delves into the original logic of the thinking of the logos as presented by Heraclitus, questioning the common ambiguity of 'logic'. This work is an indispensable contribution to the history of philosophy and offers valuable insights for students and those interested in philosophy.