L'institution comme réalisation du collectif

This article draws connections between two approaches on the question of institutional dynamics, the economics of conventions and the regulation theory. In a first section, Popper's conception of objectivity is used to explain relations between rules and regularity in conducts and expectations. In a second section, three levels in rules are distinguished, which, together, constitute institutions. In a third section, the normative dimension of these rules is analysed, and the idea of legitimacy examined. In a fourth section, institutional dynamics are shown to rely on two components : uncertainty and (bounded) reflexivity. Building on these four sections, a general definition of institutions is offered as a conclusion.