MARCO PANZA is Research Professor at the CNRS. He is the author and editor of several books and papers in the domains of history and philosophy of mathematics. Including Analysis and sinthesis in Mathematics (ed., with M. Otte), 1997; Isaac Newton, 2003; Newton et l'origine de l'analyse, 1664-1666, 2005; Nombres. Eléments de mathématiques pour philosophes, 2007.ANDREA SERENI is Lecturer at San Raffaele University, Milan, Italy. He has been a visiting scholar at Arché Centre at the University of St. Andrews. He has taught courses at the Universities of Modena and Reggio Emilia, Parma, and Bologna. His teaching, research and publications cover philosophy of mathematics, epistemology, and philosophy of language.

• Preface Terminological Conventions Introduction The Origins From Frege to Gödel (through Hilbert) Benacerraf's Arguments Non-conservative Responses to Benacerraf's Dilemma Conservative Responses to Benacerraf's Dilemma The Indispensability Argument: Structure and Basic Notions The Indispensability Argument: The Debate Conclusion Notes References Index