Castoriadis’s encounter with autopoiesis was a decisive factor for his philosophical trajectory. Its influence can be seen on four interconnected levels of his thought: his reconsideration of Greek sources for his later interpretation of trans-regional being as self-creating; his rethinking of objective knowledge; his ventures into philosophical cosmology; and his re-evaluation of the living being, especially in light of his dialogue with Varela. In brief, Castoriadis’s engagement with autopoiesis was significant for his shift towards an ontology of radical physis. His (...) shift to radical physis does not point so much to a rejection of the project of autonomy, however, as, paradoxically, its simultaneous radicalization and relativization. (shrink)