Alessandro Arbo is maître de conférences in the Music Department of the University of Strasbourg. Author of many essays in aesthetics and philosophy of music, he edited, among other things, Perspectives de l'esthétique musicale: entre théorie et histoire (Paris 2007). More recently he published Archéologie de l'écoute. Essais d'esthétique musicale (Paris 2010). Dr Michel Le Du is Maître de Conférences at the Faculty of Philosophy of the University of Strasbourg. He has written extensively on Wittgenstein, especially in connection with philosophy of social sciences and philosophy of psychology. He has published La nature sociale de l'esprit, Wittgenstein, la psychologie et les sciences humaines (Paris, Vrin, 2005). Sabine Plaud is a French scholar in philosophy, focusing mostly on the work of Ludwig Wittgenstein. She dedicated her PhD thesis to the notion of pictorial language in Wittgenstein's work, and she published several papers on this author. She is the co-editor of a French Companion to Wittgenstein (Lectures de Wittgenstein, Paris Ellipses, 2012). She also produced significant contributions in analytic philosophy: in particular, she published a French translation of W.V.O Quine's The Ways of Paradox, and she also co-edited a Companion to analytic philosophy (Lectures de la philosophie analytique, Paris, Ellipses, 2011).