Abstract
A phenomenological reading of Pierre Maine de Brian (1766-1824) offers a valuable understanding of one's own body in relation to the ego's apperceptive effort. As an organic mass, the body follows the double movement of this effort, manifested by an inner and an outer resistance. This movement allows the „constitution” of the world as correlative to the deployment of a force, identified with the apperception of the ego itself. This practical radicalization of the cogito can be viewed as the first outstanding achievement of phenomenology itself, even prior to its historical foundation by Husserl.