The thesis of the epistemological rupture and the thesis of continuity between the young and the adult Marx share the supposition that it is in the Marxian theoretical production where the constitution of historical materialism is defined. However, Mazora offers an alternative thesis in which through a meticulous work, it shows that in Capital Marx takes from Engels substantive references to develop his theory. Therefore his thesis could be summarized in the formula Young Engels, teacher-Young Marx, disciple.