The development of post-national democracy in Europe depends on the development of an overarching communicative space that functions as a public sphere, viz., a common room created by speakers who are discussing common affairs in front of an audience. This is a place where opinions ideally are formed and changed according to a communicative mode or interaction. The point of departure is Habermas' seminal work on the public sphere from 1962. The author examines the aptness of his recent reformulation of the concept (1992/1996), which is found to be too 'thin'. Further, he distinguishes between a general public sphere, segmented publics and strong publics and clarifies their potential conduciveness to democratic government. General publics are inclusive and open communicative spaces rooted in civil society in the periphery of the political system. Such a sphere is found wanting at the supranational level in Europe. Rather what is discovered are transnational, segmented publics evolving around policy networks constituted by the common interest in certain issues, problems and solutions. The EU also has many strong publics, viz. legally institutionalized discourses specialized on collective will-formation close to the center of the political system.