ABSTRACT
Cosmopolitanism is radical in the most common, political-ideological sense when it pushes the principle of world citizenship to extremes, setting this principle against the status quo. Cosmopolitanism is radical in the etymological sense when it goes to the root, core, or essence of the idea. This chapter argues that the best candidate for a radical cosmopolitanism in both senses is a tradition of revolutionary politics that first emerged in modern Europe but quickly moved beyond it. Radical cosmopolitanism is universalistic, but it expresses the universal as insurgent, as challenging what is taken for universal in a particular time and place. Insurgent radical cosmopolitanism can thus denote the agent and author of a process of universalization that is destined to oppose dominant forms of universalism again and again. Optimism is an intrinsic property of the radical cosmopolitan tradition of insurgent universality, to open politics to new actors, subjects, and concerns, and to spur the transformation of politics itself.
