Merleau-Ponty’s relationship with his Sorbonne professor Léon Brunschvicg is usually disregarded or mentioned by scholars as a mere anecdote. Moreover, the rare discussions of the latter’s “critical idealism” usually take at face value Merleau-Ponty’s partial and biased account. In contrast, this paper argues that in order to understand the genesis of Merleau-Ponty’s thought, it is necessary to reassess Brunschvicg’s idealism and his views on the relationship between perception and scientific knowledge. Particular attention is drawn to a specific chapter of Brunschvicg’s (...) masterwork L’Expérience humaine et la causalité physique, entitled “Théorie intellectualiste de la perception”. Therein is articulated the theory of perception that Merleau-Ponty never ceased to contest, and of which his entire oeuvre constitutes a reversal. However, far from highlighting only the elements of opposition, the author also points out the thematic continuity that survives the generational gap between the two authors. (shrink)