  More than just reconstructing an implicitly normative know-how, Habermas is clear that such reconstructive sciences have a “quasi-transcendental” status by specifying very general and formal conditions of successful communication. In this way, their concern with normativity and with the abilities needed for rationality in Habermas’s practical and social sense permits them to acquire a critical role. Certainly, the goal of the reconstructive sciences is theoretical knowledge: they make such practical know-how explicit. But insofar as they are capable of explicating the conditions for valid or correct utterances, they also explain why some utterances are invalid, some speech acts unsuccessful, and some argumentation inadequate. Thus, such sciences “also explain deviant cases and through this indirect authority acquire a critical function as well” (Habermas, 1990, 32). This authority then permits the theory of rationality to underwrite critical claims about social and political practices, to show how their functioning violates not only the espoused rules but also the conditions of rationality.