Acting as a link between his political and anthropological thought, the concept of autonomy as developed by Cornelius Castoriadis (1922-1997) shows the psychological conditions that any democratic self-institution of a society requires. As there is no individual autonomy without a collective autonomy, the expression “se gouverner sans maître” (self-government) has a double meaning, both political and psychological at the same time, hidden by the conventional and institutional approach of self-governance. Our aim in this article is to show that Castoriadis’ widely undervalued concept of psyché could be placed at the “heresy point” of the structuralist and post-structuralist wave which, being predominant in French philosophy during the Sixties and Seventies, didn’t lead but to aporetical concepts of psyché and of the unconscious, concepts that have as a common feature that of deconstructing the ideas of will and of autonomous being. While trying to avoid offering a classical and naïve idea of the latter, it’s from the unsolved problems bequeathed by this approach to the idea of psyché that Castoriadis’ reflection develops, and that we can catch the most original and topical side of a thought, whose importance still hasn’t been properly recognized.