At the beginning of the 21st century the conditio humana cannot be understood nationally or locally but only globally. This constitutes a revolution in the social sciences. The `sociological imagination' (C. Wright Mills) so far has basically been a nation state imagination. The main problem is how to redefine the sociological frame of reference in the horizon of a cosmopolitan imagination. For the purpose of empirical research I distinguish between three concepts: interconnectedness (David Held et al.), liquid modernity (Zygmunt Bauman) (...) and cosmopolitization from within. The latter is a kind of class analysis after class analysis, which takes on board globalization internalized. For the purposes of social analysis, therefore, it is necessary to distinguish systematically between the national manifestation on the one hand and cosmopolitan reality of `global flows', currents of information, symbols, money, risks, people, social inequalities, on the other. This internal involuntary and often unseen cosmopolitanization from below of the national sphere of experience is occurring, however, with the power of economic globalization. So what does inner `cosmopolitanization' mean? The key concepts and questions of a way of life, such as nourishment, production, identity, fear, memory, pleasure, fate, power and politics, can no longer be located and understood nationally, but only globally whether in the shape of globally shared collective futures, capital flows, impending ecological or economic catastrophes, global foodstuff chains, transnational power games, or the `Esperanto' of pop music. In this article I look at transformation in the understanding of space-time, of identity, of the production paradigms, as well as at the resulting consequences for key sociological concepts like class and power and, within this frame, point to certain dilemmas of cosmopolitanism. (shrink)