Professor of Constitutional Law and Legal Philosophy, Moral and Politics at the University of Paris X, Nanterre
Member of the Institut Iniversitaire de France. Editor of several journals, such as Droits, and the Révue Francaise de Droit Constitutionnel.

Among his numerous titles, where he exposes the legal realism theory, could be found in spanish La máquina y la norma: dos modelos de constitución; Ensayos de teoría constitucional y Problemas Abiertos de la Filosofía del Derecho.