Sociology was born not when good and evil were defined by what is useful or harmful to society, but rather when this correlation, exalted by the utilitarians, was placed in doubt because individualism seemed to have become a menace to society. This disjunction of the actor and the system led the most radical thinkers to conceive of a system without actors, dominated by determinisms and impersonal powers, and others to describe actors without a system, constructing in a normative void the forms of their interaction with actors who were strangers. Homo sociologicus, exalted by political philosophy, has disappeared. The globalization of the economy, which has entailed a weakening of the social and political controls that existed at the national level, has led in return to the development of identity politics which no longer defend a function but a being, not a project but a memory, which contradicts the evolution that has long defined modernity. We cannot establish a link between the system and the actor unless the latter is defined by the construction of his or her own liberty and not by the playing of specific social roles, and the former as a civil society in which the collective conditions of individual freedom are created. Social solidarity is the condition of cultural diversity, that is to say, the possibility for each person to combine in his or her own way their identity with participation in the techno-economic world.