r r. ! i .1 I AlE Chalmers What is this thing called Science? third edition Hackett Publishing Company, Inc. Indianapolis / Cambridge ~ .. Copyright © 1976, 1982, 1999 by A. F. Chalmers Reprinted from the 1999 third edition, University of Queensland Press Box 42, St. Lucia, Queensland 4067 Australia "Like all young men I set out to be a This book is copyright. Apart from any fair dealing for the purposes genius, but mercifully laughter intervened." of private study, research, criticism or review, as permitted under the Clea Lawrence Durrell Copyright Act, no part may be reproduced by any process without written permission. Typeset by University of Queensland Press Printed in the United States of America Co-published in North America by Hackett Publishing Company, Inc. P.O. Box 44937, Indianapolis, IN 46244-0937 04 03 02 01 00 99 1 2 3 4 5 678 Library of Congress Catalog card Number: 99-71498 Paper ISBN 0-87220-452-9 Cloth ISBN 0-87220-453-7 The paper used in this publication meets the minimum requirements of American National Standard for Information Sciences - Permanence of Paper for Printed Library Materials, ANSI 239.48-1984. 9 Contents Preface to the first edition xi Preface to the second edition xiv Preface to the third edition xv~ Introduction x~x 1. Science as knowledge derived from the facts of experience 1 A widely held commonsense view of science 1 Seeing is believing 4 Visual experiences not determined solely by the object viewed 5 Observable facts expressed as statements 10 Why should facts precede theory? 12 The fallibility of observation statements 14 Further reading 18 ~. Observation as practical intervention 19 JObservation: passive and private or active and public? 19 Galileo and the moons of Jupiter 22 Observable facts objective but fallible 24 Further reading 26 3. Experiment 27 Not just facts but relevant facts 27 The production and updating of experimental results 29 Transforming the experimental base of science: historical examples 31 JExperiment as an adequate basis for science 38 Further reading 40 4. Deriving theories from the facts: induction 41 Introduction 41 Baby logic 41 Can scientific laws be derived from the facts? 43 viii Contents Contents ix What constitutes a good inductive argument? 45 The function of normal science and revolutions 117 Further problems with inductivism 49 The merits of Kuhn's account of science 119 . The appeal of inductivism 53 Kuhn's ambivalence on progress through revolutIons 122 Further reading 58 Objective knowledge 124 Further reading 129 5. Introducing falsificationism 59 Introduction 59 9. Theories as structures II: Research programs 130 A logical point in favour of falsificationism 60 Introducing Imre Lakatos 130 Falsifiability as a criterion for theories 61 Lakatos's research programs 131 Degree of falsifiability, clarity and precision 65 Methodology within a program and the comparison of Falsificationism and progress 69 programs 136 Further reading 73 Novel predictions 138 Testing the methodology against history 141 6. Sophisticated falsificationism, novel predictions Problems with Lakatos's methodology 144 and the growth of science 74 Further reading 148 Relative rather than absolute degrees offalsifiability 74 IncreaSing falsifiability and ad hoc modifications 75 10. Feyerabend's anarchistic theory of science 149 Confirmation in the falsificationist account of science 78 The story so far 149 Boldness, novelty and background knowledge 81 Feyerabend's case against method 150 Comparison ofthe inductivist and falsificationist view of Feyerabend's advocacy offreedom 155 confirmation 83 Critique of Feyerabend's individualism 157 Advantages of falsificationism over inductivism 84 Further reading 86 Further reading 159 11. Methodical changes in method 161 7. The limitations of falsificationism 87 Against universal method 161 Problems stemming from the logical situation 87 Telescopic for naked-eye data: a change in standards 163 Falsificationism inadequate on historical grounds 91 Piecemeal change of theory, method and standards 168 The Copernican Revolution 92 A light-hearted interlude 171 Inadequacies of the falsificationist demarcation criterion Further reading 173 and Popper's response 101 Further reading 103 12. The Bayesian approach 174 Introduction 174 8. Theories as structures I: Kuhn's paradigms 104 Bayes'theorem 175 Theories as structures 104 Subjective Bayesianism 177 Introducing Thomas Kuhn 107 Applications of the Bayesian formula 181 Paradigms and normal science 108 Critique of subjective Bayesianism 187 Crisis and revolution 112 Further reading 192 x Contents 13. The new experimentalism 193 Introduction 193 Preface to the first edition Experiment with life of its own 194 Deborah Mayo on severe experimental testing 198 Learning from error and triggering revolutions 202 This book is intended to be a simple, clear and elementary The new experimentalism in perspective 205 introduction to modem views about the nature of science. Appendix: Happy meetings of theory and experiment 210 When teaching philosophy of science, either to philosophy Further reading 212 undergraduates or to scientists wishing to become familiar with recent theories about science, I have become increas­ 14. Why should the world obey laws? 213 ingly aware that there is no suitable single book, or even a Introduction 213 small number of books, that one can recommend to the Laws as regularities 214 beginner. The only sources on the modem views that are Laws as characterisations of powers or dispositions 217 available are the original ones. Many of these are too difficult Thermodynamic and conservation laws 221 for beginners, and in any case they are too numerous to be Further reading 225 made easily available to a large number of students. This book will be no substitute for the original sources for anyone 15. Realism and anti-realism 226 wishing to pursue the topic seriously, of course, but I hope it Introduction 226 will provide a useful and easily accessible starting point that Global anti-realism: language, truth and reality 227 does not otherwise exist. Anti-realism 232 My intention of keeping the discussion simple proved to be Some standard objections and the anti-realist response 233 reasonably realistic for about two-thirds of the book. By the time I had reached that stage and had begun to criticise the Scientific realism and conjectural realism 238 Idealisation 241 modem views, I found, to my surprise, first, that I disagreed with those views more than I had thought and, second, that Unrepresentative realism or structural realism 243 Further reading 246 from my criticism a fairly coherent alternative was emerging. That alternative is sketched in the latter chapters of the book. 16. Epilogue 247 It would be pleasant for me to think that the second half of Further reading 253 this book contains not only summaries of current views on the nature of science but also a summary of the next view. Notes 254 My professional interest in history and philosophy of sci­ Bibliography 256 ence began in London, in a climate that was dominated by the Index of names 264 views of Professor Karl Popper. My debt to him, his writings, his lectures and his seminars, and also to the late Professor Imre Lakatos, must be very evident from the contents of this book. The form of the first half of it owes much to Lakatos's brilliant article on the methodology of research programs. A noteworthy feature of the Popperian school was the pressure - Preface to the first edition xiii xu Preface to the first edition I hope I will not upset any?ne by s~ngling out Jean Curthoys it put on one to be clear about the problem one was interested and Wal Suchting for speCIal mentIon here. in and to express one's views on it in a simple and straight­ Lucky and attentive readers will detect m thIS .book t.he forward way. Although lowe much to the example of Popper odd metaphor stolen from Vladimir Nabokov, and wIll reahse and Lakatos in this respect, any ability that I have to express that lowe him some acknowledgment (or apology). myself simply and clearly stems mostly from my interaction I conclude with a warm "hello" to those friends who don't with Professor Heinz Post, who was my supervisor at Chelsea care about the book, who won't read the book, and who had College while I was working on my doctoral thesis in the to put up with me while I wrote it. Department of History and Philosophy of Science there. I Alan Chalmers cannot rid myself of an uneasy feeling that his copy of this Sydney, 1976 book will be returned to me along with the demand that I rewrite the bits he does not understand. Of my colleagues in London to whom lowe a special debt, most ofthem students at the time, Noretta Koertge, now at Indiana University, helped me considerably. I referred above to the Popperian school as a school, and yet it was not until I came to Sydney from London that I fully realised the extent to which I had been in a school. I found, to my surprise, that there were philosophers influenced by Wittgenstein or Quine or Marx who thought that Popper was quite wrong on many issues, and some who even thought that his views were positively dangerous. I think I have learnt much from that experience. One of the things that I have learnt is that on a number of major issues Popper is indeed wrong, as is argued in the latter portions of this book. How­ ever, this does not alter the fact that the Popperian approach is infinitely better than the approach adopted in most philoso­ phy departments that I have encountered. lowe much to my friends in Sydney who have helped to waken me from my slumber. I do not wish to imply by this that I accept their views rather than Popperian ones.