According to the received view, Marxian (ideology) critique and Foucaultian (genealogical) critique constitute two divergent approaches of critical theory that have remarkably different goals and little in common. In this article, however, we identify a guiding thread that connects the Marxian and Foucaultian traditions and motivates a distinctive approach within critical theory we call the ‘critique of constitution’. The problem of restricted consciousness, we show, is the core problem in common between Michel Foucault's critical history of thought and Georg Lukács's (...) theory of reification which underlies the tradition of Western Marxism and Frankfurt School critical theory. The problem concerns the limits of intelligibility and, by the same token, the apparent inevitability of the given social ontology. Our sense of what is possible depends on what we are able to think. But we know from the history of sciences that the limits of intelligibility change, thereby also altering our sense of what is possible. This becomes a political problem in connection with the intelligibility of social reality, because our restricted consciousness limits the alternatives we can so much as consider and seek to bring about. The critique of constitution, then, aims to expand the scope of possibility by revealing the contingent formation of the given limits of intelligibility. We argue that this is the paramount political task for Foucault and Lukács alike, other important differences notwithstanding. (shrink)