Always associated to a purposive behavior, the economic rationality is often confused with the utility maximizing behavior. This association is not always valid, since the maximizing form of individual rationality is not indépendant from its social context. This article deals with the link between the rationality of the individual behavior and the structure of the social organization, using the interdépendant couple "Rule of Behavior" - "Rule of Organization" . Three different models are presented : maximizing rationality and walrassian market , improving rationality and edgeworthian market , teleologic rationality and marshallian market .Toujours associée à un calcul intéressé , la rationalité économique est souvent confondue avec le compo...