To characterize the man in Jean-Jacques Rousseau she is necessary to have in mind the way as it reconstructs the history of the humanity, showing that the existing inaquality between the men is fruit of the action of the proper men throughout history. Through this reconstruction the author works the State of Nature and the Civil State. Rousseau says that the property becomes the beginning of the inaquality of the men and defends that only an organized society can reveal the divisions of the properties, as many private properties as public, but being always the private property a common good. For the distant philosopher the more the man will be of the Civil State, of the rationality, better the man if he becomes, therefore he believes that what ruins the man is the society, is the rationality and is for this reason that Rousseau wants the return of the man for its State of Nature. The author was the first philosopher to question the rationality, that for it the rationality was not something negative, therefore the way as being something positive, but yes, because it was come back toward the things superfluous and not essential to the men and for this reason contests that it. It does not believe that the rationality was used for being the rational man and yes for interest. For the thinker the man must be independent and therefore he believes that only the education cannot be only one way of instruction, but yes a pedagogia of the autonomy. Rousseau believes a Social Contract where the people is who decides, where the laws are determined by the people, it had the notion of public good, where only with public good if it would arrive then at an organized society that had prescribed the properties. For Rousseau the scientific ascension was not folloied by a moral ascension, human being, for it and as he himself at the beginning says Of the Social Contract ' ' the man is born exempts, and for all the part meets acorrentado' '.