  Habermas's (D)-Principle articulates this dialogical requirement. If one assumes this requirement, then one can arrive at Habermas's specific conception of reasonable moral discourse by working out the implications of his argumentation theory for the discursive testing of unconditional moral obligations. What one gets is a dialogical principle of universalization (U): “A [moral norm] is valid just in case the foreseeable consequences and side-effects of its general observance for the interests and value-orientations of each individual could be jointly accepted by all concerned without coercion” (i.e., in a sufficiently reasonable discourse) (1998a, 42; trans. amended). Habermas maintains that (U) can be deduced from statements articulating the pragmatic implications of argumentative discourse over moral norms (1990a, 86–93; 1998a, 39–45). More precisely, a successful deduction probably depends on three assumptions: (D), a statement of the semantics of unconditional norms, and an articulation of the pragmatics of discourse (Rehg 2011; cf. Ott 2004). If we accept (D) and if we accept Habermas's explication of the rhetorical presuppositions of the discursive justification required by (D), then (U) would have to follow as an implication of what is required for discursively justifying norms with the specific content of moral norms, namely obligations that bind persons in general and whose acceptance thus affects each person's pursuit of interests and the good life. From the standpoint of argumentation theory, (U) seems to state the burden of proof that structures an adequate process and procedure of justification.