Effective argumentation in international politics is widely conceived as a matter of persuasion. In particular, the 'logic of arguing' ascribes explanatory power to the 'better argument' and promises to illuminate the conditions of legitimate normative change. This article exposes the self-defeating implications of the Habermasian symbiosis between the normative and the empirical force of arguments. Since genuine persuasion is neither observable nor knowable, its analysis critically depends on what scholars consider to be the better argument. Seemingly, objective criteria such as universality only camouflage such moral reification. The paradoxical consequence of an explanatory concept of arguing is that moral discourse is no longer conceptualized as an open-ended process of contestation and normative change, but has recently been recast as a governance mechanism ensuring the compliance of international actors with pre-defined norms. This dilemma can be avoided through a positivist reification of valid norms, as in socialization research, or by adopting a critical and emancipatory focus on the obstacles to true persuasion. Still, both solutions remain dependent on the 'persuasion vs. coercion' problem that forestalls an insight into successful justificatory practices other than rational communication. The conclusion therefore pleas for a pragmatic abstention from better arguments and points to the insights to be gained from pragmatist norms research in sociology.
