"Reaching and understanding is the process of bringing about an agreement on the presupposed basis of validity claims that are mutually recognized."

“If we compare the third-person attitude of someone who simply says how things stand (this is the attitude of the scientist, for example) with the performative attitude of someone who tries to understand what is said to him (this is the attitude of the interpreter, for example), the implications … become clear. … First, interpreters relinquish superiority that observers have by virtue of their privileged position, in that they themselves are drawn, at least potentially, into negotiations about the meaning and validity of utterances. By taking part in communicative action, they accept in principle the same status as those whose utterances they are trying to understand. … It is impossible to decide a priori who is to learn from whom.”

“[Critical social science attempts] to determine when theoretical statements grasp invariant regularities of social action as such and when they express ideologically frozen relations of dependence that can in principle be transformed.”

“All affected can accept the consequences and the side effects that [the norm's] general observance can be anticipated to have for the satisfaction of everyone's interests, and the consequences are preferred to those of known alternative possibilities for regulation.”

“[According to Habermas, the genesis of the bourgeois public sphere resulted from a combination of early capitalist commercial development and the organization of territorial … Representative publicness involved a re-presenting or staging for the purposes of display and acclamation, hence] this publicness (or publicity) of representation was not constituted as a social realm, that is, as a public sphere; rather, it was something like a status attribute, if this term may be permitted.”

“The 'state' on the modern conception is a legally defined term which refers, at the level of substance, to a state power that possesses both internal and external sovereignty, at the spatial level over a clearly delimited terrain (the state territory) and at the social level over the totality of members (the body of citizens or the people). State power constitutes itself in the forms of positive law, and the people is the bearer of the legal order whose jurisdiction is restricted to the state territory. In political usage, the concepts 'nation' and 'people' have the same extension. But in addition to its legal definition, the term 'nation' has the connotation of a political community shaped by common descent, or at least by a common language, culture, and history. A people becomes a 'nation' in this historical sense only in the concrete form of a particular form of life.”

“The speaker must choose a comprehensible [verständlich] expression so that speaker and hearer can understand one another.”