Aurélien Robert, PhD (2005) in Philosophy, is researcher at the École Française de Rome and at the Centre d'Études Supérieures de la Renaissance (CNRS). He has published several papers on medieval epistemology, and more specifically on William of Ockham.Christophe Grellard, PhD (2001) is associate professor of Philosophy at the University of Paris 1 -Sorbonne. He has published Croire et savoir. Les principes de la connaissance selonz Nicolas d'Autrécourt (Vrin, Paris, 2005) and numerous articles on medieval epistemology and history of sciences.