The aim of this research is to delineate, within the Sartrian thought of the Sixties, the mobile perimeter inside which to define ethics as the overcoming possibility for a critical thought. In other words: as the subjective assumption of its political dimension. The shift of Sartre’s historical-political thought follows a development not yet studied enough by scholars. The manuscripts of the Sixties about dialectical ethics appear as the fundamental completion of the dialectical experience of the Critique de la Raison dialectique (1960). Sartre was not able to publish the second part of the book during his life: indeed, the blockage of that work is the result of the structural limit of every attempt to conceptualize historical experience. In the Critique, the possibility to make a single history intelligible depends on a refoundation of dialectics as research method for concrete historical reality. Starting by such refoundation, it becomes possible to define the epistemological basis of a historical structural anthropology, and the conditions for the insurgence of human collective action at the same time. In our interpretation, this approach is out of a future perfect’s logic that means out of the core of the modern sovereignty’s system. Once fixed those points, the research moves around two principal problematic axis. The first evaluates the methodological and epistemological accuracy of Sartre’s attempt to formulate a theory of knowledge for Marxism, considering this one as a theoretical-practical experiment yet to be done. At this point, Sartre’s regressive-progressive method is compared to Marx’s method of critique of political economy, evaluating affinity aspects and overcoming lines. Around the second axis, transverse to the first, the more properly historical-political plexus finds its profile: the dialectical comprehension of events connoting subjectively (that means politically) historical time’s flow isn’t detachable from questioning about the historicity of subjects involved in this flowing. For this reason, in the Sartrian thought of the Sixties the subjectivity’s status is analyzed questioning the normative disposition of social sphere: focusing on normativity allows to understand the mutual implication of subjectification and objectification, in addition to locating basis for a Marxist axiology. Moreover, this perspective allows to improve historical effectiveness of praxis’s ethical dimension. This one is the lens by which Sartre analyzes both Stalinism and colonial liberation struggles, but also the point of clarification of the torsion he imposes to the notion of longing. Materialistically, with the longing Sartre discovers the root of an ethics as the necessary step for every politics.