Real Time [1 ed.] 0521241332, 9780521241335

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Real Tim e D. H. M E L L O R

C A M B R ID G E U N I V E R S I T Y PRESS Cambridge London New York Melbourne Sydney

New Rochelle

Published by the Press Syndicate of the University of Cambridge The Pitt Building, Trumpington Street, Cambridge CB2 1RP 32 East 57th Street, New York, NY 10022, USA 296 Beaconsfield Parade, Middle Park, Melbourne 3206, Australia © D H Mellor 1981 First published 1981 Printed in Great Britain at the Pitman Press, Bath British Library Cataloguing in Publication Data

Mellor, D. H. Real time. 1 Time I Title 115 BD638 81-3841 ISBN 0 521 24133 2

To the memory o f F. P. Ramsey whose work I should most like to he able emulate.

Contents

Preface 1 2 3 4 5 6 7 8 9 10

Introduction and summary Dates and tenses Tense and token-reflexives The presence of experience Tenseless time and tenseless space The need for tense The unreality of tense Change Events, causes, things and parts The direction of time Prediction, time travel and backward causation Bibliography Index

ix 1 13 29 47 58 73 89 103 119 140 160 188 201

Preface

This book derives originally from talks on time broadcast by the Australian Broadcasting Commission in 1975 and later, revised, by the BBC; so I would thank Julie Anne Ford o f the ABC and Fraser Steel o f the BBC for encouraging me to write the talks, thereby setting me off on the book. I was in Australia in 1975 as a Visiting Fellow in the Philosophy Department of the Research School of Social Sciences at the Australian National University, to whom I am much obliged for enabling me to go there and discuss all sorts o f things, including time. To many philosophers and others whom I met in Canberra, Sydney, Melbourne, Adelaide and Brisbane, I owe the great pleasure and mental profit of my visit. In Canberra I was pleasantly and profitably provoked by a class on time run by Genny Lloyd and Bill Godfrey-Smith, whose intense and ingenious devotion to real tenses made me think the tenseless truth could still do with some help from its friends, and so decided me to write a book about it. O f philosophers elsewhere in Australia, Graham Nerlich and Jack Smart have most influenced my thinking about time. Since 1975 I have developed the ideas in this book through many discussions and lectures at Cambridge and elsewhere, and learned a lot from comments made on those occasions by colleagues and students. In particular, my reconstruction in chapter 6 of M cTaggart’s argument against real tenses owes much to sugges­ tions and corrections made by Timothy Smiley. Besides that, my views on time have been most affected - one way or another - by the graduate research I have been privileged to supervise o f Bill Godfrey-Smith, Huw Price and Jeremy Butterfield. Jeremy But­ terfield, especially, now a Cambridge colleague and a close friend, has taught me more than anyone else about the relevance of physics and the semantics o f tense. Outside Cambridge, two recent discussions of my work on time have been exceptionally valuable to me. One was at a meeting in

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Preface

March 1979 of the Thyssen United Kingdom Philosophy Group which discussed inter alia a first draft of my ‘McTaggart, fixity and coming true’, referred to below. (I have also had helpful comment on that work from David Lewis and John Mackie, and at a seminar at the University of Arizona in early 1979, arranged by Wesley Salmon.) The other was in a class on time I gave at Stanford University in 1978, which I am indebted to Nancy Cartwright for arranging and examining as well as contributing to. To John Perry, then Head of the Philosophy Department there, I owe thanks for its hospitality as well as for ideas on indexicals freely appropriated in chapter 5. The Stanford class was part of a six-month visit to the USA from October 1978, when I lived in Berkeley and was, through the good offices of Barry Stroud, allowed to use the Library and other facilities of U .C . Berkeley’s Philosophy Department, and so given the chance of pertinent and useful conversations with its students and faculty. My work on time in the USA was also furthered by the help and friendship of Ian Hacking and Nancy Cartwright, John and Sue Shively, Isaac and Judy Levi and, above all, Edwin Almirol. The visit itself came at the start of my two-year Radcliffe Fellowship, during which the book was virtually done and without which it would not have been. So I must here render especial thanks to the Radcliffe Trustees and their advisers for awarding me the Fellowship, and to my Cambridge colleagues for granting me exceptional leave to take it up. My American excursion during it was made possible by a much appreciated Overseas Visiting Fellowship from the British Academy. I am grateful also for two other contributions made by the British Academy to this book. They made me their Henriette Hertz Lec­ turer for 1979, which provided an occasion to develop and try out most o f the material o f chapter 10 as ‘The possibility of prediction’, read to the Academy on 3 May 1979; and in 1977 they gave money for compiling an annotated bibliography of recent work on time and other metaphysical matters. It was the basis of the bibliography at the end o f this book, to which I owe much more than (for reasons given in the Introduction) I acknowledge in the text. I am corres­ pondingly indebted to those who compiled and annotated it for me: David West, John Dupre, Peter Smith and Jeremy Butterfield. The actual writing of the book was kept going by encourage­ ment, not to say pressure, from Jeremy M ynott and Jonathan