What obligations do we have to distant others, and how and where do we draw the boundaries of our belongings? Taking an empirical and critical sociological lens, this presentation addresses the crucial research agenda cosmopolitan questions pose for the twenty-first century. An ancient concept, cosmopolitanism has also been at the forefront of innovations in the contemporary social sciences and humanities. It is seen by some as a successor, or perhaps as an ethical or cultural extension, to globalisation theory. Considered a bedrock process of social solidarity in global times, cosmopolitanisation processes may allow people to reflexively reconsider local and national loyalties as the primary basis for social and cultural interaction. Research findings are presented that deal with key cosmopolitan questions around belonging, obligations to others, and encounters with diversity. Methodologically, the presentation reflects on connections between moral judgement, cognitive processes, and cultural repertoires.