This book is the first biography devoted to one of the greatest intellectual and political figures of the 20th century, Cornelius Castoriadis (1922-1997). Young Greek revolutionary resistant threatened with death by the Stalinists, he arrived in France at the age of twenty-three, when the exaltation aroused by the USSR was at his zenith. He then contributed to creating, together with Claude Lefort and Jean-François Lyotard, one of the most active groups of the radical left, Socialism or Barbarism, which would later become a mythical magazine and one of the great influences of May '68. , especially for his left-wing criticism of so-called “communist” regimes.

Economist, philosopher, psychoanalyst, political militant, Castoriadis is the author of an essential work for anyone interested in the question of the institution outside the framework of the State, a topic he deals with in what can be considered one of the masterpieces of the century. XX, The imaginary institution of society (1975). In a cross between historical analysis and the psychoanalytic approach, Castoriadis, in effect, did not stop consecrating himself to thinking about the conquest of autonomy as a condition of democratic deepening.

The result of an investigation carried out with a hundred testimonies, this work finally makes it possible to lift the veil that covered this figure out of all norms and too unknown, who occupied a marginal position until the end, despite his election as director of studies at the Écoles des hautes études en sciences sociales at the beginning of the 1990s. The one whom Pierre Vidal-Naquet saw as a “genius” and Edgar Morin as a “titan of the spirit”, is nevertheless destined, in these times of great turbulence of the established sovereignties, to become, without a doubt, one of the key thinkers of the 21st century.