Abstract
This article is a plea for a realist view of deliberative bodies against a nominalist view. They cannot be reduced to the changing collection of the individuals who compose it. The deliberative bodies are real collective entities insofar as we are able to precise their criteria of identity. These are the differentiation between an interior and an exterior linked by functions or ends; thus these collective entities are adaptive systems. There are three kinds of such adaptive systems: technical systems, organisms and human organizations. The specificity of human organizations is related to the nature of the relations between parties, which are normative, and to the way their ends are determined. Deliberative bodies are organizations of which the specific characteristics have been listed. The mode of being of these collective entities is adverbial. This means that the existence of a deliberative body is subordinated to the nature of the activity of its members and to the manner they are oriented toward its instituted ends.