Contemporary writing on cosmopolitanism has asserted the need for a new sociological toolkit to deal with an emergent post-national social order. At the heart of this agenda is a misunderstanding about the role of the nation-state, which has led to some rather unhelpful theorizations. The state is assumed to be a dead hand in the development of post-national sentiments or an increasingly irrelevant social structure. We argue that the superseding of the nation-state is not necessary for the development of cosmopolitan sentiments of solidarity. In addition to classical sociology, it is work surrounding the concepts of cosmopolitan democracy and constitutional patriotism and the public sphere that can assist us in theorizing cosmopolitanism. What distinguishes this tradition is the utilization of social science concepts such as democracy, state, public sphere and law in an attempt to ground the idea of cosmopolitanism within the context of existing social structures.