Few concepts in social theory have been used so extravagantly in recent years as the notion of power. Yet, despite its inflated presence, the term is still unclear and under-theorized. In The Circular Structure of Power, Torben Dyrberg rises to the challenge of conceptualizing power through a philosophical examination of its uses in contemporary social theory. Drawing on the insights of Michel Foucault, Ernesto Laclau and Chantal Mouffe, Dyrberg brings this continental tradition into a creative dialogue with the Anglo-American tradition represented by figures such as Steven Lukes, William Connolly, Peter Bachrach and Morton Baratz. Moreover, Dyrberg moves from such abstract considerations to their implications for political and democratic theory through an examination of the work of thinkers as diverse as Robert Dahl, John Rawls, Jurgen Habermas and Nicos Poulantzas. Simultaneously engaging with and defying many of the dominant definitions of power, Torben Dyrberg destabilizes and undermines the conventional distinctions and polarities through which power is usually understood. The new perspective offered to us by this investigation is one which goes beyond the assumption that power can be based on and derived from either agency or structure, as if these categories were not somehow constituted by power.