Intellectual movements in the Arab world resist their reduction to cohesive schools consisting of common conceptual and theoretical grounds. It is difficult, if not impossible, to bring the works of several intellectuals under a common school, whether Marxists, phenomenologist, existentialists, or structuralists. The coordinates of Marxism, for example, once rooted in the Soviet-communist, as well as Arab nationalist, party-forms, underwent a process of transformation in the 1960s. Similarly, Arab intellectuals indebted to Sartrean existentialism could be seen as having had undergone a seismic shift when Sartre fell out of vogue with Arab intellectuals in the wake of the 1967 defeat. Intellectuals such as Georges Tarabishi, Lutfi al-Khuli, Muta’ Safadi, and Mohamad Amin al-Alim were heavily indebted to existentialism despite their divergent political commitments. What remains common in these intellectual pursuits is their aim to produce a new concept of history by positing new historical epistemologies. The two most illustrative figures are the Lebanese theoretician Mahdi Amel and the Moroccan philosopher and historian Abdallah Laroui, who both sought to transform the prevailing concept of history in Arab thought. In order to do that, they, separately, sought to revise contemporary Arabic theoretical practice in light of Marxist thought. Their interest in Arab thought, and its critique, was not to salvage it, but to transmute it into a modern critical discourse—a process referred to as a “Kantian revolution” by Amel, and a “Copernican revolution” by Laroui. This was to be accomplished not by mere conceptual translation of Marxian terminology into Arabic, but by thinking the antagonisms and deadlocks governing Arab post-colonial social formations and producing theoretical systems addressing them. In both Amel and Laroui, there is a confluence of the history of science with the science of history—between historical epistemology and historical materialism. However, their respective projects varied in philosophical orientation and scope, and diverted in key areas. Starting from the question of underdevelopment or temporal lag, they proceeded by defining the conceptual grounds using their own analytic categories of critique before building their theoretical structures. Their respective systems presented competing definitions of modernity and mapped different relations between the specific and the universal. In this paper, I aim to return to modern Arab intellectual debates to remap the coordinates of intellectual production. Taking Amel and Laroui as two exemplars, I explain the transformation of the conceptual categories in the work of some of the chief intellectual figures of the period.