THE EXPANDING CIRCLE THE EXPANDING CIRCLE Ethics, Evolution, and Moral Progress Peter Singer With a new aftervvord by the author PRINCETON Ul\;IVERSITY PRESS PRINCETON A�D OXFORD Copyright© 1981 by Peter Singer New preface and afterword copyright© 2011 by Peter Singer Requests for permission to reproduce material from this work should be sent to Permissions, Princeton UniversityPress Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock, Oxfordshire OX20 1 TW press.princeton.edu Originallypublished by Farrar, Straus & Girouxin 1981 First Princeton University Press paperbackedition, with new preface and afterword, 2011 All Rights Reserved Library of Congress Control Number: 2010937652 ISBN: 978-0-691-15069-7 British LibraryCataloging-in-Publication Data is available Printed on acid-free paper. oo Printed in the United States of America 1 3 5 7 9 10 8 6 4 2 For Renata The moral unity to be expected in different ages is not a unity of standard, or of acts, but a unity of ten­ dency.... At one time the benevolent affections em­ brace merely the family, soon the circle expanding includes first a class, then a nation, then a coalition of nations, then all humanity, and finally, its influence is felt in the dealings of man with the animal world. -w. E. H. LECKY, The History of European Morals CONTENTS Preface to the 2011 Edition xi Preface XV 1 I The Origins of Altruism 3 2 I The Biological Basis of Ethics 23 3 From Evolution to Ethics? 54 4 Reason 87 5 I Reason and Genes 125 6 A New Understanding of Ethics 148 Notes on Sources 175 Afterword to the 2011 Edition 187 Index 205 PREFACE TO THE 2011 EDITION The Expanding Circle may well have been the first book-length attempt to assess the implications of "sociobiology" for our un­ derstanding of ethics. Since its appearance in 1981, there has been a stream of books and articles on the origins and develop­ ment of ethics, and during the last decade, especially, a dramatic increase in the quantity and quality of scientific investigation into how we make moral judgments. It is pleasing to find that the book's central theses have gained additional support from this research. It is now generally accepted that the roots of our ethics lie in patterns of behavior that evolved among our prehu­ man ancestors, the social mammals, and that we retain within our biological nature elements of these evolved responses. We have learned considerably more about these responses, and we are beginning to understand how they interact with our capacity to reason. Many philosophers now recognize the relevance of this work to our understanding of ethics. In the afterword I de­ scribe some of the scientific research that has taken place in the last decade, and its significance for the views I set out in the original text. I also explain why, if I were writing the book today, I would be more open to the idea of objective reasons for action and objective truth in ethics than I was thirty years ago. I have placed this discussion at the end of the book because for most readers it will make more sense when read after the main text, xii I PREFACE TO THE 2011 EDITION but of course those who are impatient to be brought up to date may read it first. The term "sociobiology" was coined by E. 0. Wilson in his 1975 book Sociobiology: The New Synthesis, a pioneering multi­ disciplinary study that aroused a storm of controversy because Wilson applied theories about the evolution of social behavior­ in organisms as different as bees and chimpanzees-to humans, thus challenging our cherished idea that we are entirely distinct from nonhuman animals. Wilson made a significant contribution to our understanding of human nature, but in writing about eth­ ics, he committed a fallacy common among scientists who turn their attention to that field. Wilson's misunderstanding of the import of his own work for ethics provided the impetus for me to write this book, both to explain the fallacy he was making, and to demonstrate that despite it, Wilson's approach does help us to understand the origins of ethics. Hence in the text that follows Wilson's writings receive closer scrutiny than the work of any other scientist. Those parts of sociobiology that relate to human beings are now referred to as "evolutionary psychology." Although the ap­ plication of sociobiology to human beings was fiercely opposed by some researchers, the development of evolutionary psychol­ ogy has had a calmer reception. To that extent, the rebranding has been a resounding success, although one could also argue, less cynically, that the growing acceptance of evolutionary psy­ chologyis due to the merits of the studies it has produced, rather than the change of name. If thirty years ago most philosophers were disdainful of what scientists wrote about ethics, that may have been because some scientists suggested that the scientific breakthroughs they were making could be not merely relevant to, but a substitute for, the thinking that philosophers do about ethics-what I refer to at PREFACE TO THE 2011 EDITION I xiii the beginning of chapter 3 as "The Takeover Bid." Just when you might think this misconceived scientific challenge to ethics has finally been dispatched, it pokes its head up again. In 2007 Nicholas Wade, writing in the New York TirMs, referred to "the biologists' bid to annex" moral philosophy, and the following year the Economist published an essay headed "Moral Thinking: Biology Invades a Field Philosophers Thought Was Safely Theirs.''• For the reasons set out below, it is a mistake to believe that scientific findings could be a substitute for the kinds of thinking that philosophers do about, and in, ethics. I hope that this new edition will help to make it clear (again!) why such at­ tempts are bound to fail, and why philosophers are right to con­ tinue to reject such attempts to annex ethics or moral philoso­ phy, while they should welcome scientific help in understanding the origins and nature of ethics as a human phenomenon. In conclusion, I will mention one apparently trivial way in which this book has dated, which could turn out to be much more significant than it appears. In chapter 4, as part of an inci­ dental example, I mention the typewriter I was using to write the book. Three years later the typewriter was abandoned and I started writing on a computer. That made editing easier, saved paper, and avoided the need to use unhealthy-smelling correc­ tion fluid. But the digitalrevolution turned out to be much more far-reaching than that. Recording our thoughts digitally, rather than on paper, means that they can be sent electronically, and the availability of instant, virtually free communication all over the world is affecting every aspect of our lives, including our ethics. In another passage from chapter 4 I quote Gunnar Myrdal's An ArMrican Dilemma, a major study of attitudes • Nicholas Wade, "Scientist Finds the Beginnings of Morality in Primate Behavior," New York Times, March 2, 2007; Economist, February 21, 2008. xiv I PREFACE TO THE 2011 EDITION about race and racism published in 1944. In Myrdal's view, greater social mobility, more intellectual communication, and more public discussion were already then contributing to a change in the racist attitudes that had existed for so long in some parts of the United States. If more mobility and more communi­ cation were already making a difference in 1944, what should we expect from the vastly greater changes that are happening now, linking people all over the world, and opening up commu­ nities that hitherto had little access to ideas from outside? The experiment is under way, and there will be no stopping it. What it will do for the rate at which we make moral progress and ex­ pand the circle of those about whom we are concerned, remains to be seen. Peter Singer Princeton, New Jersey, 2010 PREFACE Ethics is inescapable. Even if in grim adherence to some skeptical philosophy we deliberately avoid all moral lan­ guage, we will find it impossible to prevent ourselves in­ wardly classifying actions as right or wrong. The skepticism that eschews all ethical judgment is possible only when all goes tolerably well: Nazi atrocities refute it more convinc­ ingly than volumes of philosophical argument. Recognizing that we cannot do without standards of right and wrong is one thing; understanding the nature and origin of these standards is another. Is ethics objective? Are moral laws somehow part of the nature of the universe, like the laws of physics? Or are they of human origin? And if they are of human origin, are there standards of right and wrong that all human beings should accept, or must ethics always be rela­ tive to the society in which we live, perhaps even to the per­ sonal attitudes of each one of us? Systematic Western philosophy goes back 2,500 years, and discussions of the nature of ethics date from the start of that period. Human beings have thought about these issues from the time they first began to inquire into the nature of their world and their society. Unlike our inquiries into the nature of the physical universe, however, two and a half millennia of moral philosophy have still not yielded generally accepted results about the fundamental nature of ethics. For centuries, religion provided a way out of this diffi­ culty. It is natural for those who believe in God to look to his xvi I I'HEF:\CE wishes or commands for the origin of morality.