Paul Benacerraf is Stuart Professor of Philosophy at Princeton University. He has been a John Simon Guggenheim Fellow and a Fellow of the Center for Advanced Study in the Behavioral Sciences. His publications include Logicism: Some Considerations ( 1960), Philosophy of Mathematics (ed. with H. Putnam) ( 1964; second revised edition 1983); "'What Numbers Could Not Be'" ( 1965), "'God, the Devil, and Gödel'" ( 1967), "'Mathematical Truth'" ( 1973), "'Frege: The Last Logicist'" ( 1981), and "'Skolem and the Skeptic'" ( 1985).
George Boolos was Professor of Philosophy at the Massachusetts Institute of Technology. He was Vice-President of the Association for Symbolic Logic and an editor of the Journal of Symbolic Logic. His publications include Computability and Logic (with R. C. Jeffrey) ( 1974), The Unprovability of Consistency: An Essay in Modal Logic ( 1979), Meaning and Method: Essays in Honor of Hilary Putnam (ed.) ( 1990), and The Logic of Provability ( 1993). He is also the author of numerous articles on logic and the philosophy of mathematics and on Frege. He died on 27 May 1996.
John P. Burgess is Professor of Philosophy at Princeton University. He has been an editor of the Journal of Symbolic Logic. His many publications on logic and the philosophy of mathematics include "'Forcing'" ( 1977), "'Why I Am Not a Nominalist'" ( 1983), "'Synthetic Mechanics'" ( 1984), "'The Truth is Never Simple'" ( 1986), "'Non-Classical Logic and Ontological Non- Commitment'" ( 1995). His book (with G. Rosen) A Subject with No Object: Strategies for Nominalistic Reconstrual of Mathematics was published in 1997 by Oxford University Press.
Charles S. Chihara is Professor of Philosophy at the University of California at Berkeley. His chief research interests are in the philosophies of mathematics and logic, philosophical logic, and metaphysics. He is the author of Ontology and the Vicious Circle Principle ( 1973), Constructibility and Mathematical Existence ( 1990), and Worlds of Possibility ( 1998). He has also published many articles in the areas of his research interests.
Michael Detlefsen is Professor of Philosophy at the University of Notre Dame, where he is also editor-in-chief of the Notre Dame Journal for Formal Logic. He is subject-editor in logic and philosophy of mathematics for the forthcoming encyclopaedia of philosophy by Routledge. He has visited at the philosophical faculty of the University of Split and the department of philosophy of the University of Konstanz. He is the author