David Lewis Philosophy Now Series Editor: John Shand This is a fresh and vital series of new introductions to today’s most read, discussed and important philosophers. Combining rigorous analysis with authoritative exposition, each book gives a clear, com- prehensive and enthralling access to the ideas of those philosophers who have made a truly fundamental and original contribution to the subject. Together the volumes comprise a remarkable gallery of the thinkers who have been at the forefront of philosophical ideas. Published Donald Davidson Robert Nozick Marc Joseph A. R. Lacey Michael Dummett W. V. Quine Bernhard Weiss Alex Orenstein Saul Kripke Richard Rorty G. W. Fitch Alan Malachowski Thomas Kuhn John Searle Alexander Bird Nick Fotion David Lewis Charles Taylor Daniel Nolan Ruth Abbey John McDowell Peter Winch Tim Thornton Colin Lyas Forthcoming David Armstrong John Rawls Stephen Mumford Catherine Audard Nelson Goodman Wilfrid Sellars Daniel Cohnitz & Marcus Rossberg Willem deVries Thomas Nagel P. F. Strawson Alan Thomas Clifford Brown Hilary Putnam Bernard Williams Max de Gaynesford Mark Jenkins David Lewis Daniel Nolan First published 2005 by Acumen Published 2014 by Routledge 2 Park Square, Milton Park, Abingdon, Oxon OX14 4RN 711 Third Avenue, New York, NY 10017, USA Routledge is an imprint of the Taylor & Francis Group, an informa business © Daniel Nolan, 2005 This book is copyright under the Berne Convention. No reproduction without permission. All rights reserved. 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Contents Acknowledgements vi Introduction 1 1 Metaphysical and scientific realism 5 2 The Humean mosaic 27 3 The plenitude of possibilities 51 4 Laws, causes, dispositions and chance 80 5 Realism and reductive materialism about the mind 115 6 Representation and mental content 135 7 Language, use and convention 157 8 Values and morality 178 9 Some reflections on Lewis’s method 203 Notes 229 Bibliography 238 Index 243 v Acknowledgements I owe thanks to many people for assistance and encouragement while writing this book. I won’t even try to mention all the people who encouraged me. In addition to encouragement, Steffi Lewis was kind enough to provide me with copies of forthcoming Lewis papers and provided me with a bibliography of his works. Particular thanks also to those who gave me feedback on one or more chapters: Alan Hájek, Ishani Maitra, L. A. Paul and especially Chris Daly, who gave me much useful feedback on many chapters. Thanks to the School of Anthropological and Philosophical Studies at the University of St Andrews for giving me leave to write this book, and thanks to the several Australian departments that made me feel welcome during the composition: the philosophy department at Monash University, the philosophy program at the Australian National University, and the philosophy discipline at the University of Queensland. Thanks to the series editor, John Shand, and to Steven Gerrard at Acumen, for giving me the opportunity to write this book. Thanks to Robert Williams for the index and Kate Williams for copy-editing. Finally, my greatest gratitude goes to my family, who made me welcome and cheerfully put up with me while I was writing. Page numbers in citations throughout the text refer to the col- lected editions of Lewis’s works, but the original publication date is also given in square brackets to give the reader a sense of the chronol- ogy of publication. Daniel Nolan St Andrews vi Introduction David Lewis’s work is among the most influential in many areas of contemporary philosophy, but much of his influence has been as a “philosopher’s philosopher”: his main impact to date has been on the work of other professional philosophers. His work deserves a broader audience, since it is full of thought-provoking ideas, breadth of vision, a clear and incisive treatment of issues and plain good sense. He deals in a straightforward and unpretentious manner with many of the deepest philosophical issues, and his picture of the world and our place in it is one that deserves to be widely known. Lewis’s work covers topics in many of the central areas of philoso- phy: metaphysics, philosophy of language, philosophy of mind, decision theory, philosophy of mathematics, epistemology, philosophical logic, philosophy of science, value theory and many others. Despite this, his views have a unity to them. A comprehensive philosophical system emerged gradually from Lewis’s writings, somewhat of a rarity in Anglo-American philosophy in the second half of the twentieth cen- tury. It emerged somewhat unexpectedly, even for Lewis. “I should have liked to be a piecemeal, unsystematic philosopher, offering inde- pendent proposals on a variety of topics. It was not to be,” he com- mented in the introduction to his first volume of collected papers. Indeed, many of his readers may only have a vague idea of how his views fit together, since it is possible to engage in one set of issues dealt with by Lewis without engaging very much in the others. His papers on causation, laws of nature, chance and conditionals, for example, form a connected body of work, but a philosopher could be heavily engaged with Lewis’s ideas on those topics without knowing much about, say, his views about language and meaning and convention. This book is David Lewis intended to provide an overview of Lewis’s contributions in different areas, both well-known contributions, such as his views in metaphys- ics, and less well-known ones, such as his contributions to ethics. Those who have come across Lewis’s work in one area may find this book use- ful to get a sense of how his different projects relate to each other. While I hope this book might be useful to those who already know something of Lewis’s work, no familiarity with any of Lewis’s writings nor any philosophical background are presupposed, except perhaps inadvertently. Apart from anything else, Lewis’s work does have an impact in areas outside philosophy, and those concerned with linguis- tics, game theory or cognitive science may be just as interested in an overview of his work as those with more narrowly philosophical concerns. Lewis’s written work includes four influential books and approxi- mately 100 articles (including responses, critical notices and so on), and his philosophical interests are very wide-ranging, so on occasion this book may resemble a whistle-stop tour rather than a detailed critique. In particular, I have not tried to discuss all of Lewis’s more technical works. Lewis’s contributions to formal semantics, the foun- dations of mathematics, decision theory, game theory and other tech- nical areas are important, and they have significant philosophical implications. I shall certainly address some of the philosophical implications, but those seeking a discussion, for example, on the effect on the semantics of conditionals flowing from Lewis’s triviality results (1976b, 1986e), or Lewis’s contributions to deontic logic (e.g. 1988b, 1974b), will find little here. In particular, I decided with regret not to attempt to convey Lewis’s work in the philosophy of mathematics. This is not because I think his book and articles on the topic are not valuable, but rather for reasons of space and accessibil- ity. Some of Lewis’s important contributions to the formal under- standing of languages, for example his paper “General Semantics” (1970) or his work on double-indexing, are also topics I shall not attempt to address because of their technical level. I urge readers who are interested in any of the topics discussed to read Lewis for themselves. He has an entertaining and clear style, and deals with issues in much greater depth than I could allow myself in reporting and discussing his work. Many of his papers are as valuable for their introductory sections as for Lewis’s actual posi- tions and arguments. He has a way of introducing the issues in a dispute, or clearing up confusions along the way, so that a paper yields useful understanding of philosophical problems even before 2 Introduction the reader realizes the paper is underway. Lewis is often a pleasure to read, and one of my hopes for this book is that it will lead people to discover that pleasure for themselves. David Lewis was born in 1941, and his philosophical writings span the period from 1966 to the time of his death in 2001 (and more than half a dozen posthumous papers are still appearing or due to appear). Lewis did his graduate work at Harvard, and his supervisor was W.