Garner, John V. "Castoriadis, Cornelius." (INTERNET ENCYCLOPEDIA OF PHILOSOPHY).

Cornelius Castoriadis was an important intellectual figure in France for many decades, beginning in the mid-1940s. Trained in philosophy, Castoriadis also worked as a practicing economist and psychologist while authoring over twenty major works and numerous articles that span most of the traditional philosophical subjects, including politics, economics, psychology, anthropology, and ontology. While his works exhibit a vast range of specialized expertise, his oeuvre can be understood broadly as a reflection on the creativity of individuals and of society, on the opposition of traditional ontology to the fact of radically creative humanity, and, perhaps most importantly, on the dangerous political and ethical consequences of a contemporary world that has lost sight of autonomy, that is, a world that ignores the urgency to give limits or laws to itself.
Influenced by his understanding, and often criticism, of traditional philosophical figures such as the pre-Socratics, Plato, Aristotle, Kant, Fichte, Hegel, Marx, and Heidegger, Castoriadis was also influenced by thinkers as diverse as Sigmund Freud, Max Weber, Maurice Merleau-Ponty, and Georg Cantor. Castoriadis had dynamic intellectual relationships with his fellow members of Socialisme ou Barbarie (including Claude Lefort and Jean-François Lyotard, among others) as well as with leading figures in mathematics, biology, and other fields.

Perhaps above all, Castoriadis will be remembered for his initial support and then break with Marxism, for his subsequent call for Western thought to embrace the reality of creation in a radical sense (and, in particular, to embrace the fact of human creativity at individual and societal levels), and, finally, for his defense of an ethics and politics based on autonomy, or giving the law to oneself, which is never the autonomy of an isolated being but always involves beings who relate to others and are aided by institutional supports. In the end, for Castoriadis, the central question of philosophy, and the source of philosophy’s importance, is its capacity to creatively break through society’s closure and ask what the relevant questions for humans can be or ought to be. . . .

http://www.iep.utm.edu/castoria/