Viewed from a theoretical and empirical perspective, the ongoing process of Europeanization poses new challenges to sociology. As a science, sociology reveals the inadequacy of the conceptual and methodological instruments currently available for our understanding of European social phenomena. Sociologists fi nd it di cult to defi ne the very object under scrutiny: does a European society exist? How should we defi ne a society whose boundary lines are variable? Does a study of Europe from a sociological perspective entail a study of the European Union, or of a broader social formation? e di culty encountered in "studying Europe" in the sociological area is linked to a broader theoretical debate which, in the light of the ongoing processes of change, queries the entire cognitive apparatus and the theoretical paradigms developed by sociological disciplines and related to the modernity of the western world. e "national constellation" of norms, institutions and regulative techniques which have allowed political and social integration within the national state, are now challenged by phenomena which undermine their very epistemological foundations. e concepts applied to the study of social and political integration, - society, state, legitimacy, social inequality, mobility, justice, solidarity, etc.- are, in a classic defi nition of the term, no longer e cient in discerning the phenomena which impact on contemporary societies. e variety of themes discussed by several Italian and foreign authors explore many aspects of the workings of Europe; they reveal new theoretical and methodological perspectives with which we set out to study the political, social, cultural and economic phenomena which today characterize Europe.