Éducation et Sociétés has followed the development of the comprehensive project in different French-speaking countries. The contexts are extremely different and the contribution presented here will only examine the case in France. The current middle school is not the one that had been molded by left-wing education specialists since the 1920s. Middle schools are places of suffering as much for teachers as for the students. The inequalities are increasing: the results of the PISA survey have just pointed this out without triggering more than an expression of polite compassion. How can we explain this drift ? There have been a few striking measures in the last thirty five years: the decentralization law of 1981; the LOLF which introduced the principles of the New Public Management in the French administration. These two laws only had limited effects. In terms of contents, the law of 2005 introduced the principle of a “common core of knowledge and skills” which evokes European standards. Ten years later, it is difficult to know how this reform has been implemented. The local interpretations of laws and regulations and players’ strategies undoubtedly have an important role.