M. R. Bennett is Professor of Neuroscience, University Chairand Scientific Director of the Brain and Mind Research Institute atthe University of Sydney. He is the author of many papers and bookson neuroscience as well as the history and philosophy ofneuroscience, including The Idea of Consciousness (1997) and A History of the Synapse (2001). He is past President of theInternational Society for Autonomic Neuroscience, past President ofthe Australian Neuroscience Society, as well as the recipient ofnumerous awards for his research, including the Neuroscience Medal,the Ramaciotti Medal, the Macfarlane Burnet Medal and the Order ofAustralia. P. M. S. Hacker is an Emeritus Research Fellow of StJohn s College, Oxford, UK. He is the author of numerousbooks and articles on philosophy of the mind and philosophy oflanguage, and is the leading authority on the philosophy ofWittgenstein. Among his many publications is the four-volumeAnalytical Commentary on Wittgenstein's PhilosophicalInvestigations, and its epilogue, Wittgenstein's Place inTwentieth Century Analytic Philosophy. His most recent work isHuman Nature: The Categorial Framework, the first volume ofa trilogy on human nature. Together, M. R. Bennet and P. M. S. Hacker have authored theacclaimed Philosophical Foundations of Neuroscience(Blackwell, 2003).