Jean-Jacques Rousseau, one of the great philosophers of 18th century, was not considered like a man of letters in France. Most of critiques consider Rousseau one of the great theorists of politics and education. In fact, he edified a great system of his thoughts with his two Discourses. He did not pretend to have created this system all of a sudden, but he had continually enriched it up to the work that he considered like a final statement of his thoughts. J.-L.Lecercle, Jean-Jacques Rousseau, Paris, Larousse, 1973. There is on a larger plan a deep unity of his works, which guide throughout his works. It shows to the human-being the way of happiness which was at the same time the common goal of 18th century. It contains several times the essence of his thoughts in a single phrase : “The nature made man happy and good, but the society depraved him and made him miserable." Rousseau, Dialogues, Paris, Gallimard, Édition de la Pléiade, Vol.1,1959. First of all, his works are the one of the moral philosophy looking for a happiness, but it is evident that it's impossible to reach there through the way of the individual ego. Therefore the ego must be looked for through the education forming the new man. Rousseau became in this way educator. Then he criticized severely the society, betraying its vice in the Discourse of the sciences and the arts. And then he proposed the solution in Emile, concerning the education to form a new man. The result of the education purifies progressively the entire society. Our research takes care of humbly outlining the critique of the society and the solution by the education according to the method of J.-L. Lecercle.