Riddles of Existence A Guided Tour of Metaphysics The questions of metaphysics are among the deepest and most puzzling. What is time? Am I free in my actions? What makes me the same person I was as a child? Why is there something rather than nothing? Riddles of Existence makes metaphysics genuinely accessible, even fun. Its lively, informal style brings the riddles to life and shows how stimulating they can be to think about. No philo- sophical background is required to enjoy this book. It is ideal for beginning students. Anyone wanting to think about life’s most profound questions will find Riddles of Existence provocative and entertaining. Earl Conee is Professor of Philosophy at the University of Rochester, New York. Theodore Sider is Professor of Philosophy at New York University. This page intentionally left blank Riddles of Existence A Guided Tour of Metaphysics Earl Conee and Theodore Sider CLARENDON PRESS OXFORD 3 Great Clarendon Street, Oxford ox2 6dp Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide in Oxford New York Auckland Cape Town Dar es Salaam Hong Kong Karachi Kuala Lumpur Madrid Melbourne Mexico City Nairobi New Delhi Shanghai Taipei Toronto With offices in Argentina Austria Brazil Chile Czech Republic France Greece Guatemala Hungary Italy Japan Poland Portugal Singapore South Korea Switzerland Thailand Turkey Ukraine Vietnam Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries Published in the United States by Oxford University Press Inc., New York ß Earl Conee and Theodore Sider 2005 The moral rights of the authors have been asserted Database right Oxford University Press (maker) First published 2005 First published in paperback 2007 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above You must not circulate this book in any other binding or cover and you must impose the same condition on any acquirer British Library Cataloguing in Publication Data Data available Library of Congress Cataloging in Publication Data Data available Typeset by SPI Publisher Services, Pondicherry, India Printed in Great Britain on acid-free paper by Clays Ltd, St Ives plc ISBN 978–0–19–928226–5 (hbk) 978–0–19–921518–8 1 3 5 7 9 10 8 6 4 2 contents List of Figures vii Introduction 1 1. Personal Identity 7 2. Fatalism 22 3. Time 44 4. God 62 5. Why Not Nothing? 87 6. Free Will and Determinism 112 7. Constitution 134 8. Universals 154 9. Possibility and Necessity 181 10. What is Metaphysics? 197 Acknowledgments 207 Index 209 This page intentionally left blank list of f igures 1. The movement of a train defined by reference to time 45 2. The moving of the present moment 46 3. High-school physics graph of a particle moving through time 48 4. Space-time diagram 49 5. Where is the ‘real here’? 51 6. ‘Now’ for me and for Guy Fawkes 52 7. Moving back and forth in space 55 8. Moving back and forth in time, temporal axis vertical 56 9. Moving back and forth in time, temporal axis horizontal 56 10. Four-dimensional perspective on the clay statue 148 11. David Lewis’s actual and possible worlds 193 This page intentionally left blank Introduction You have a choice before you. Will you continue reading this book? Take your time, make up your mind . . . OK, time’s up. What is your decision? If you have reached this sentence, your decision must have been yes. Now, think back to your decision. Was it a free decision? Could you have put the book down? Or did you have to keep reading? Of course you could have put the book down; of course your decision was free. We human beings have free will. Not so fast. We human beings are made of matter, tiny particles studied by the sciences. And the sciences, especially physics, discover laws of nature that specify where these particles must move. Given the forces that were acting on the particles, your body had to move the way it did, and so you had to continue to read. How then was your decision free? This is the problem of free will. It is a tough problem. We all believe that we have free will, and yet scientiWc laws govern the matter making up our bodies, determining what we will do next. So do we have free will? Chapter 6 discusses this problem in depth, and suggests a certain answer. But it is not so important to us that you agree with our answer. What we really hope is