"[T]he most original, ambitious, and reflective attempt to think through the liberating mediation of history, society, external and internal nature once again as praxis". -- Jü rgen Habermas, "The Philosophical Discourse of Modernity" "Castoriadis"s "The Imaginary Institution of Society" is a work of great power and originality. As a work of social theory, I would argue that it belongs in a class with the writings of Habermas and Arendt". -- Jay Bernstein, University of Essex This is one of the most original and important works of contemporary European thought. First published in France in 1975, it is the major theoretical work of one of the foremost thinkers in Europe today. Castoriadis offers a brilliant and far-reaching analysis of the unique character of the social-historical world and its relations to the individual, to language, and to nature. He argues that most traditional conceptions of society and history overlook the essential feature of the social-historical world, namely that this world is not articulated once and for all but is in each case the creation of the society concerned. In emphasizing the element of creativity, Castoriadis opens the way for rethinking political theory and practice in terms of the autonomous and explicit self-institution of society.