I present the contours of an explanatory model of legitimacy that directs the focus away from normative questions and onto specific mechanisms of reality construction at play in constituting social orders. The key assumption informing the model is that stable orders rely fundamentally on their capacities to construct separate spheres of social reality, by which they exempt critical parts of reality from the burden of legitimation. I argue that an order's legitimacy ultimately depends on its ability to confine the question (...) of legitimacy by relegating authorship of reality to opaque sources that are separated epistemically from the institutional order. The effective reification of critical zones of reality is shown to be a functional precondition for institutional stability. I show that capitalist democracy, in particular, depends on this mode of constructing ‘passive legitimacy’, which constitutes a key obstacle for any attempt to transform it towards an ecologically and socially sustainable formation. (shrink)