Required by the theorists of deliberative democracy, the argumentative norm is underdetermined in the eyes of the theorists of argumentation. This paper lays out several elements of an argument and dismisses those who play storytelling against it and those who demand it without defining it otherwise than in a minimalist way. Exploring some causes for deliberation (conflicts, uncertainties, modalities), it loosens the grip of political philosophy (Habermas, Rawls) on moral philosophy and on moral theories pluralism. It proposes an institutionally favored division of argumentation labor, to avoid the risk of emptying deliberative democracy of its meaning.