Every metaphysic, according to Reiner Schürmann, involves the positing of a first principle for thinking and doing whereby the world becomes intelligible and masterable. What happens when such rules or norms no longer have the power they previously had? According to Cornelius Castoriadis, the world makes sense through institutions of imaginary significations. What happens when we discover that these significations and institutions truly are imaginary, without ground? Both thinkers begin their ontologies by acknowledging a radical finitude that threatens to destroy (...) meaning or order. For Schürmann it is the ontological anarchy revealed between epochs when principles governing modes of thinking and doing are foundering but new principles to take their place have not yet emerged. For Castoriadis it is chaos that names the indeterminationdetermination that governs the unfolding of the socio-historical with contingency and unpredictability. And yet for both thinkers their respective ontologies have political or ethical implications. On the basis of the anarchy of being, Schürmann unfolds an anarchic praxis or ethos of “living without why.” And on the basis of his notion of being as chaos, Castoriadis develops his political praxis of autonomy. The challenge for both is this move from ontology to practical philosophy, how to bridge theory and practice. The key for both seems to be a certain ontologically derived sense of freedom. In this paper, I analyze and compare their respective thoughts, and pursue the question of how anarchy or chaos and the implied sense of an ontological freedom might be made viable and sensible for human praxis, how radical finitude in the face of ontological groundlessness might nevertheless serve to situate a viable political praxis. (shrink)