According to Jürgen Habermas, his Theory of Communicative Action offers a new account of the normative foundations of critical theory.1 Habermas’ motivating insight is that neither a transcendental nor a metaphysical solution to the problem of normativity, nor a merely hermeneutic reconstruction of historically given norms, is sufficient to clarify the normative foundations of critical theory. In response to this insight, Habermas develops a novel account of normativity, which locates the normative demands of critical theory within the socially instituted practice of communicative understanding.Although Habermas has claimed otherwise, this new foundation for critical theory constitutes a novel and innovative form of “immanent critique.” To argue for and to clarify this claim, I offer a formal account of immanent critique and distinguish between two different ways of carrying out such a critique. I examine Habermas’ rejection of the first, hermeneutic option. Against this background, I then show that the Theory of Communicative Action attempts to formulate an immanent critique of contemporary societies according to a second, “practice‐based” model. Such a practice‐based model of immanent critique differs from a hermeneutic model insofar as it locates the norms, which the critique employs, within the rules of common social practices, rather than within shared understandings. However, because Habermas commits himself to an implausibly narrow view in regard to one central element of such a model – in regard to what I will call the “social ontology of immanent normativity” – his normative critique cannot develop its full potential.