While they have been historically essential to the legitimacy of states and democracies, notions of “public”, “private” and “the commons” have increasingly blurred over the past decades. Large multinational companies or consulting groups nowadays claim to be acting in the name of “public interest” through actions in the field of corporate social responsibility, philanthropy, and outsourcing of “public service” activities; states increasingly organize along “businesslike” models of performance, and claim to act on financial and economic markets as if they were “private actors”; grassroots movements and local communities, for their part, have rediscovered the notion of “Commons” as a challenge to both markets and governments, through shared property and self-management of common goods or resources (ocean fisheries, water supply, public spaces, etc.). The course will provide conceptual tools and sociological insights to make sense of this increasingly complex cartography by drawing on different types of literature in the fields of Political Economy, Law, Geography, History and Political Science.