In On a raison de se révolter Sartre identifies in idealistic unrealism, in amoralistic realism, and in materialistic and moralistic realism, the three decisive moments in his intellectual development. In the light of these caesuras, which interweave the gnoseological and the moral problem and find a possible key of interpretation in the progressive semantic mutation of the authenticity-unauthenticity dichotomy, the author intends to redesign the path that leads from absolute freedom, through the discovery of history and the theoretical redefinition of the notion "freedom-world-others", to freedom as "total praxis". If man’s ontological difference runs through Sartre’s entire work and guides his critique of dialectical materialism, in the post-war writings that difference begins to be rethought within the historical horizon of the dialectical process of work (subjection- liberation). In presenting the morality-history relationship as inescapable, this horizon resolves the gnoseological (truth) and the moral (freedom) problem in the revolutionary philosophy of work. With his adherence to historical materialism, to which Sartre lays claim in the Critique de la raison dialectique, and the dialectical connection between historical subject and method, the writings that appeared after May ’68 place within the dialectic of freedom the problem of the "total meaning" of the life of man and indicate in the «reign of freedom», of Marxian memory, the telos of history.
Keywords: Ontological difference, work, dialectic, revolutionary humanism, materialistic and moralistic realism, praxis