This seminar explores the tradition and the contemporary revival of cosmopolitan political thought. Reaching back to classical political philosophy, cosmopolitan thought had long disappeared from Western political and moral thinking. Only after the genocides of the 20th century and the arrival of the “global age” did cosmopolitanism slowly begin to (re-)enter the center stage of debates in political theory and beyond. By now, however, “cosmopolitanism is back” (David Harvey). This seminar will deal with several distinct strands of cosmopolitan political philosophy in the context of the history of political ideas, reaching from approaches that conceive cosmopolitanism as a moral obligation of citizens in a nationally circumscribed republic to justifications of a world state and of global public law. Yet the primary focus will be on contemporary debates and future paths of cosmopolitan thinking in a post-Westphalian political environment. Political philosophers and theorists who will be discussed include Cicero, Immanuel Kant, Karl Marx, John Rawls, Hannah Arendt, Jürgen Habermas, Martha Nussbaum, David Held, Kwame Anthony Appiah, Seyla Benhabib, Jeremy Waldron, Bonnie Honig, James Bohman, and Daniele Archibugi.