The three main concepts of Lukács’ famous book History and Class Consciousness are already contained in the title: History, Class and Consciousness. 1 These three concepts are especially developed in the longest and most important essay of the book, “Reification and the Consciousness of the Proletariat”. 2 I will bring these three concepts “ Class — Consciousness — History ” together into a single thesis, which is that Lukács’ reification essay combines these concepts in an existentialist way . More precisely, he unites them into the first great existential blueprint of communist revolution. 3 My aim is to radicalize with this “existential” the common interpretations of Lukács which claim that, in his critique of alienation and reification, he brought questions of subjectivity, consciousness and praxis into the Marxism of his time, and that his “Praxisphilosophie” transformed traditional Marxism into what would later be called “Western Marxism”. My thesis instead claims that Lukács’ existentialist critique of capitalism accomplished the same kind of radicalization that Kierkegaard had done for religion long before him, and that Heidegger did for ontology shortly after him.