 That the concepts Althusser derived from his symptomatic reading of Marx, Lenin, and Mao were Marxist concepts was avowed. Nevertheless, Althusser also acknowledged that some of the concepts found latent in these texts were derived from and consistent with his philosophical and social scientific contemporaries as well as with those of Spinoza. Of course, this is not inconsistent with the theory of reading and authorship that underwrites a symptomatic reading of a text. Inasmuch as authors and readers are always said to think with concepts borrowed from or supplied by the problematic that they inhabit, there is no such thing as an innocent or objective reading: we understand things with and through the concepts available to us. Perhaps nowhere is this borrowing more evident than in Althusser’s ideas about how scientific and philosophic knowledge is generated. Though Althusser is very careful to back up his arguments about Marx’s epistemology with close analyses of Marx’s work, it is apparent that the model for knowledge acquisition that is developed in Reading Capital owes much to Spinoza and to the French tradition of historical epistemology.