Oskari Kuusela is Lecturer in Philosophy at the University of East Anglia. He is the author of The Struggle Against Dogmatism: Wittgenstein and the Concept of Philosophy (Harvard UP, 2008) and the co-editor of Wittgenstein's Interpreters: Essays in Memory of Gordon Baker (Blackwell, 2007). Professor Marie McGinn is Professor Emerita of the University of York, and Professor of Philosophy at the University of East Anglia. She is author of Sense and Certainty (Blackwell, 1989), Wittgenstein and the Philosophical Investigations (Routledge, 1997), Elucidating the Tractatus: Wittgenstein's Early Philosophy of Logic and Language (OUP, 2007), and Wittgenstein and the Philosophical Investigations, 2nd Edition (Routledge, forthcoming).