This article proposes a contribution to the comparative analysis of cultural policies by focusing on the nationally differentiated processes through which categories of public intervention in cultural matters are constructed and institutionalised. This general perspective is applied to local cultural policies in France and Germany. In order to show the formation and displacements of frontiers in these policies, we have chosen to study the linkages between "social" logics (in the sense of social policies) and more specifically cultural logics in local public action. One can thereby observe an apparently analogous see-saw movement in the two countries: the overlapping of the "social" and the "cultural" in the 1960s and 1970s, followed by a specialisation of cultural policies leading to the sidelining of the "social", and finally the rediscovery since the 1990s of objectives based on social integration in the conduct of cultural policies. The comparison nevertheless shows that the sociopolitical logics underlying these changes differ substantially from one country to the other, producing differentiated combinations of the social and the cultural.