Jaś Elsner is Humfry Payne Senior Research Fellow at Corpus Christi College, Oxford, Visiting Professor of Art History at the University of Chicago and Senior Research Keeper at the British Museum. His publications include numerous articles and books including Imperial Rome and Christian Triumph: The Art of the Roman Empire AD 100–450 (1998) and Roman Eyes: Visuality and Subjectivity in Art and Text (2007). Michel Meyer is Professor of Rhetoric, Philosophy and Aesthetics at the Université Libre de Bruxelles. He has published many works of philosophy, covering literary criticism, rhetoric, the passions, art, theatre and Roman art. Several of his works have appeared in English. He is known to be the father of a new philosophy based on the priority of questioning in thought, called problematology. Recent books include Rome et la naissance de l'art européen (2006) and Principia Rhetorica (2008).