According to the principle of charity, we always have to make the assumption that other people are rational when we try to interpret their behavior. This paper is a critical discussion of the principle and its methodological consequences in the light of recent advances in cognitive science concerning mentalization. We argue that the validity of the charity principle is limited by the likely existence of interpretative non-theoretical mechanisms (simulation theory). As a consequence, we claim that theories of rationality, scientific theories of cognition and behavior and products of mentalization can neither in fact nor in principle be identified with one another.Selon le principe de charité, nous devons toujours faire l'hypothèse qu'autrui ...