This article speaking about Rousseau's biographical books, tries to show the relation between this side of his works and his philosophical system. The biographical books by Rousseau have not only one personal value but they try to resolve theoretically and practically the separation between his live and his philosophy. This dilemma have not just as result the wihthdrawal inside of the beautiful soul but it promotes the social change demanding the personal change and the engagement of the intellectual with his work and his public opinion. Specially this article emphasizes the writing problem.