The paper addresses the ontological, epistemological and political status of intersectional categories, in a general context of categorial destabilization combined with a continued need for addressing collectivities, such as women. Drawing on the meta-theoretical tools of critical realism, I delineate a way of conceptualizing the ontology of intersectional categories which honours their ontological irreducibility and distinctness while avoiding homogenization and fixity. I centre the issue of the separateness versus inseparability of intersectional categories, suggesting that many conflicts in debates about intersectionality could be solved if we become clearer about what we mean by ‘separate’ or ‘inseparable’. The paper offers a (dialectical) critical realist solution to the in/separability tension, pivoting around the claim that things can be both separate and inseparable, at the same time.