This article reconstructs Herbert Marcuse’s first and widely ignored philosophical project, as set out in his texts published from 1928 to 1933. In these texts, Marcuse tried to put in dialogue ideas from Heidegger and Marx to articulate a dialectic phenomenology of historical existence. This attempt, of great originality and philosophical ambition, was marked by tensions arising from the peculiar status given to the ontology of historicity in a framework of thought that maintained strong links with Marx. By analysing this (...) early philosophical project of one of the icons of the international student movement, theoretical tensions can be detected, which clarify the subsequent approach of this thinker as a member of the so-called Frankfurt School. (shrink)