approximated it is always counterfactual (because, in this case, the fact is that all meanings are to some degree personally defined). Another, basic idealized presupposition of argumentation is the presupposition that no relevant argument is suppressed or excluded by the participants. Another is the presupposition that no persuasive force except that of the better argument is exerted. There is also the presupposition that all the participants are motivated only by a concern for the better argument. There is the presupposition of attributing a context-transcending significance to validity claims. This presupposition is controversial but important (and becomes expanded and clarified in the presuppositions of discourse, see below). The idea is that participants in communication instill their claims with a validity that is understood to have significance beyond the specific context of their agreement. The presupposition that no validity claim is exempt in principle from critical evaluation in argumentation; The presupposition that everyone capable of speech and action is entitled to participate, and everyone is equally entitled to introduce new topics or express attitudes needs or desires. In sum, all these presuppositions must be assumed to be approximately satisfied in any situation of communication, despite their being necessarily counterfactual. Habermas refers to the positing of these idealized presuppositions as the "simultaneously unavoidable and trivial accomplishments that sustain communicative action and argumentation". Habermas calls discourses those forms of communication that come sufficiently close to actually satisfying these presuppositions. Discourses often occur within institutionalized forms of argumentation that self-reflectively refine their procedures of communication, and as a result, have a more rigorous set of presuppositions in addition to the ones listed above. A striking feature of discourse is that validity claims tend to be explicitly thematized and there is the presupposition that all possible interlocutors would agree to the universal validity of the conclusions reached. Habermas especially highlights this in what he calls theoretical discourses and practical discourses. These are tied directly to two of the three dimensions of validity discussed above: theoretical discourse being concerned with validity claims thematized regarding objective states of affairs (IT); practical discourse being concerned with validity claims thematized concerning the rightness of norms governing social interactions (WE). Habermas understands presupposition (5) to be responsible for generating the self-understanding and continuation of theoretical and practical discourses. Presupposition (5) points out that the validity of an understanding reached in theoretical or practical discourse, concerning some factual knowledge or normative principle,