From precise examples, this article is interested in the way Merleau-Ponty elaborates its concepts, in a continued dialogue with other thoughts. Against the interpretations which fetishize his last texts without attesting their conceptual necessity and sterilize these dialogues, this work tries to retie the subtle threads of a thought making itself in the contact, for example, of Lévi-Strauss and Sartre. To read Merleau-Ponty today requires to take the measure of its own strategies of reading and to give a precise status to its courses of Sorbonne and of the Collège de France.