[The origins and foundations of social inequalities in health]

France presents the paradox of being the country where the health system has been ranked first in the world for its overall performance and where the inequalities of mortality among men are the highest in Western Europe. This reality is little known, in part because it is little studied. The authors show how the issue of health inequalities has been recently re-discovered by researchers and scientific institutions. They attempt to explain the reasons of the delay in comparison with neighbour countries, referring to its historical background. They explore how health inequalities, long considered as natural, have progressively been seen as social. The problem of definition and qualification is therefore of the utmost importance. Two conditions are necessary to speak of inequalities and not mere differences: the domain has to be socially valued (life or wellbeing, for instance) and the disparities must be hierarchical (social classes, occupational categories, etc.). Finally, the authors recall that the social inequalities in health are the result of structural inequalities which concerns all the fields of social activities and conditions and which reflects the level of social justice in a country at a specific moment of its history and economic development.