The title Being and Time still possesses an almost magical aura today, conferred on it by the two fascinating words that compose it. The goal of this work is to rethink the essential question underlying the whole history of philosophy: the question of the meaning of being. Heidegger deals with it in a particular way, bringing the question together in the fundamental anxieties of the contemporary age: the disenchantment of the modern world, the crisis of traditional values, the decline of metaphysics, the flight of the gods, the domination of technology, the hegemony of instrumental rationality and the search for new symbolic means for man. Starting from these assumptions, Being and Time becomes a sort of accurate seismograph, capable of identifying with surprising precision the collapses and leaks of the contemporary era and of offering us an exact x-ray of the ethical and moral conscience of our time. Hence its perennial relevance, which is fully extended into the 21st century.