The cycle of lectures given by Heidegger in 1955-56 is devoted to the analysis of a simple and seemingly insignificant provision on the basis of .. Heidegger consistently and convincingly proves that this proposition - "There is nothing without reason" - is the highest foundation of all thinking and representation and determines the entire history of Western European philosophy, and with it the path of development of technical civilization. Heidegger methodically traces the transformations that this proposition undergoes from the way in which it was put forward in a latent form by Aristotle, to its clear and categorical formulation, first carried out by Leibniz .. Heidegger establishes that, speaking of reason, this provision simultaneously, albeit implicitly, but in all cases without exception, speaks of being. Therefore, the provision on the basis is of great importance for clarifying the question of being ,. Heidegger's attention has always been focused, by , This is the only , question. in fact, The philosophical question , which , but, eluded traditional metaphysics and therefore in our time must be rethought. The collection also includes small texts and fragments of Heidegger's works relating to various periods of his work. The book is addressed to a wide range of readers interested in the history of philosophy in general, as well as the most important directions and trends of philosophy of the 20th century.