WILLIAM H. BRENNER is Professor of Philosophy at the Old Dominion University, Norfolk, Virginia, USA. His publications include Wittgenstein's Philosophical Investigations (SUNY, 1999), Elements of Modern Philosophy (Prentice-Hall, 1989) and Logic and Philosophy: An Integrated Introduction (Notre Dame, 1993). DANI LE MOYAL-SHARROCK is Lecturer in Philosophy at Birkbeck College, University of London. She has significantly contributed to highlighting the importance of Wittgenstein's later corpus. She is the author of Understanding Wittgenstein's On Certainty (Pa