On the occasion of the publication of the translation of Pierre Raymond’s text on Althusser’s materialism, we attempt an introduction to his theoretical trajectory. We begin with his conception of the conflict between materialism and idealism inLe passage au matérialismein 1973 and his thinking on the question of the history of sciences inL’histoire & les sciences, before turning our attention to his elaboration on the question of a history of mathematics and in particular of the emergence of probabilistic reasoning. Then (...) we examine his confrontation with the question of the relation between materialism and dialectics inMatérialisme dialectique et logique. After that, we proceed to his conception of the need to break with any form of teleology and finalism as the starting point for a new conception of causality, before looking atDissiper la terreur et les ténèbresof 1992 and his attempt to rethink the question of practical reason. It is in light of the above presentation that we insist on the importance of Raymond’s text on Althusser. (shrink)