Setting out from the paradox of the two opposing interpretations of Maine de Biran proposed by Merleau-Ponty and Henry, this article seeks to return to the reference to the body within effort. If two major commentators can defend contrasting interpretations on this point, this can only be because Biran himself does not clarify the link between the ego and the living body within effort. In reality, the ego remains the active pole, leaving the body passive or inert. Should activity be linked to the will? By distancing himself somewhat more from extended matter, Biran doubtless could have balanced better the polarity of the primitive fact by recognising, on the basis of a biological model, an infravoluntary activity of the body. By completely ...