The following article provides a critical reading of Cornelius Castoriadis concept of social autonomy in the context of his social theory. In the analysis of Castoriadis, at first contingency, processuality and dynamics of social relations are emphasised. In doing so, it is shown to what extent contingency of social processes and the demand for autonomy are at tension in their pragmatic implementation. Castoriadis solves this a bit too quickly in favour of a specific understanding of autonomy. The central focus of this article is on Castoriadis distinction between autonomous and heteronomous societies regarding the question of just institutions. Following a reconstruction of the argumentative and conceptual foundation of Castoriadis conception of society, some critical questions concerning Castoriadis normative concept of autonomy are posed with reference to Emmanuel Levinas thoughts about alterity.