Perhaps every engagement with the work of Maurice Blanchot, who is both a writer (doubtless in a new sense established by him himself) as well as a philosopher and political thinker, has to be an engagement with the undecidability between politics and ontology. How can the relationship between these two dimensions of the ontological and the political be thought? Can there be a separation between these dimensions? Is such a separation desirable or even necessary? And if so, why? My thesis is that this separation, which refers to a series of differences or binary oppositions such as the difference between ideality and reality, structure and empirical reality, the impossible and the possible, is complex, because it is a keeping-apart as well as the connecting of the two orders of ontology and politics in one. I call complex that which remains undecidable or, in Kantian terms, problematic. The locus of a politics of the subject will prove to be this locus of the problematical which cannot be assigned to either of the two orders, neither exclusively nor unambiguously.