Cornelius Castoriadis was possibly the most imaginative and innovative critical thinker of the second half of the twentieth century. His comprehensive thought opened new avenues in social philosophy, social and political theory and in the critical diagnosis of the time. It constitutes a key resource in understanding our present. Only in parts translated from French and of a fragmentary nature, however, Castoriadis's work is not as widely known and used as it should be. This important book will make access to this important thinker much easier from now on. Written by those current scholars who know Castoriadis's thought best, it provides the best introduction to his work and will be a key reference from now on. -- Peter Wagner, Research Professor, ICREA and University of Barcelona, Spain