The Habermas–Foucault debate, despite the excellent commentary it has generated, has the standing of an ‘unfinished project’ precisely because it occasions the interrogation of the fundamental categories of modernity, and because the lingering sense of anxiety, which continues to remain after arguments and counter-arguments, demands new interpretations. Here, I advance the claim that what gives Habermas’s criticisms of Foucault’s histories and theoretical formulations their bite is the categorial distinction he maintains between facts and rights, and by extension, between causes and (...) reasons. The Kantian distinction between de jure validity and de facto effectivity underwrites the categorial distinction between both ‘norms/facts’ and ‘reasons/causes’ conceptual pairs, which distinction, in turn, is reinforced by a picture of the natural world as matter in motion and human agency as self-determination. I want to claim that Foucault’s work enacts a critique of Habermas not by evading the problem of justification but by undermining the very distinctions Habermas needs to maintain the universal and necessary status of communicative rationality. Drawing on Jonathan Lear’s discussion of reasons and causes in relation to the unconscious, I claim that psychoanalytic discourse helps us make intelligible a type of reflection—such as one finds in Foucault’s historiography—that is at once “critical and empirical.” Moreover, the realization that the distinction between causes and reasons may not be categorial and exhaustive shows how Habermas’s insistence on the contrary leads to one particular kind of misrecognition of our practices. (shrink)