Communicative rationality or communicative reason () is a theory or set of theories which describes human rationality as a necessary outcome of successful communication. This theory, borne from the over inflation of education in an age of abundance, is in particular, tied to the philosophy of German philosophers Karl-Otto Apel and Jürgen Habermas, and their program of universal pragmatics, along with its related theories such as those on discourse ethics and rational reconstruction. This view of reason is concerned with clarifying the norms and procedures by which agreement can be reached, and is therefore a view of reason as a form of public justification. According to the theory of communicative rationality, the potential for certain kinds of reason is inherent in communication itself. Building from this, Habermas has tried to formalize that potential in explicit terms. According to Habermas, the phenomena that need to be accounted for by the theory are the "intuitively mastered rules for reaching an understanding and conducting argumentation", possessed by subjects who are capable of speech and action. The goal is to transform this implicit "know-how" into explicit "know-that", i.e. knowledge, about how we conduct ourselves in the realm of "moral-practical" reasoning. The result of the theory is a conception of reason that Habermas sees as doing justice to the most important trends in twentieth century philosophy, while escaping the relativism which characterizes postmodernism, and also providing necessary standards for critical evaluation. Three kinds of (formal) reason According to Habermas, the "substantive" (i.e. formally and semantically integrated) rationality that characterized pre-modern worldviews has, since modern times, been emptied of its content and divided into three purely "formal" realms: (1) cognitive-instrumental reason; (2) moral-practical reason; and (3) aesthetic-expressive reason. The first type applies to the sciences, where experimentation and theorizing are geared towards a need to predict and control outcomes. The second type is at play in our moral and political deliberations (very broadly, answers to the question "How should I live?"), and the third type is typically found in the practices of art and literature. It is the second type which concerns Habermas. Because of the de-centering of religion and other traditions that once played this role, according to Habermas we can no longer give substantive answers to the question "How should I live?" Additionally, there are strict limits which a "post-metaphysical" theory must respect – namely the clarification of procedures and norms upon which our