Thereby, the public sphere makes possible the emancipation of its participants. In his The Structural Transformation of the Public Sphere, Habermas presents a socio-historical study of the rise, structure and disintegration of the public sphere. He ascribes the disintegration of public dialogue to the predominance of instrumental reason, that is, of a means-end rationality, in contemporary societies. This orientation has led to the impoverishment of cultural tradition and normative structures, on which individuals draw in the process of coming to an understanding. From the critical perspective, the concepts of public sphere and debate are intrinsically connected, because the latter usually constitutes a prerequisite for public sphere to form. Simultaneously, the focus on rationality in the theory of public sphere constitutes an important characteristic and has significant impact on public discourse.
Ideas articulated by Jrgen Habermas provide one with guidance to understand the problem of rationality in public sphere and discourse. According to Bohman, Habermas developed a two-level social theory that includes an analysis of communicative rationality and a theory of modern society and modernization. From the critical perspective, the final goal of any public discourse or interaction is a mutual recognition and understanding, not the debate itself. Consequently, interaction cannot be rationalized according to the strategic selection of means, but has to be rationalized based on the reciprocal expectations that guide interaction. Habermas (1979) emphasizes that
Whereas the rationalization of purposive-rational action depends on the accumulation of true (empirically or analytically true) knowledge, the rationalizable aspect of communicative action has nothing to do with propositional truth; but has everything to do with the truthfulness of intentional expressions and with the lightness of norms (p.119)
Thus, when Habermas speaks of "rationalizing" public discourse, he does not mean imposing a pre-existing set of values, such as those presented by the concept of reason. Rather, Habermas understands by rationalization the process of freeing public debate from those forces that distort communication. These forces thereby prevent the attainment of consensus or agreement arrived free from coercion.
In an attempt to define the process of coming to an understanding, Habermas differentiates communicative action from communicative act. A communicative act involves the sharing of factual information and the coordination of action. Communicative action, on the other hand, employs language as a means towards reaching understanding. To this end, participants must have acquired what Habermas terms, communicative competence. That is, participants not only must be able to form grammatically coherent sentences, but must also have developed the ability of critical reflection. He had described this process as the starting point of socio-cultural development in Towards a Reconstruction of Historical Materialism. Now, it becomes a prerequisite for social change and, of course, public discourse and public sphere formation.
Whereas communicative acts remain indifferent to the motivations informing statements, communicative act