FUTURE GENERATIONS A CHALLENGE FOR MORAL THEORY Gustaf Arrhenius Dissertation for the Degree of Doctor of Philosophy in Practical Philosophy presented at Uppsala University in 2000. ABSTRACT Arrhenius, G. 2000: Future Generations: A Challenge for Moral Theory. viii+234#? pp. Uppsala. For the last thirty years or so, there has been a search underway for a theory that can accommodate our intuitions in regard to moral duties to future generations. The object of this search has proved surprisingly elusive. The classical moral theories in the literature all have perplexing implications in this area. Classical Utilitarianism, for instance, implies that it could be better to expand a population even if everyone in the resulting population would be much worse off than in the original. The main problem has been to find an adequate population theory, that is, a theory about the moral value of states of affairs where the number of people, the quality of their lives, and their identities may vary. Since, arguably, any reasonable moral theory has to take these aspects of possible states of affairs into account when determining the normative status of actions, the study of population theory is of general import for moral theory. A number of theories have been proposed in the literature that purport to avoid counter- intuitive implications such as the one mentioned above. The suggestions are diverse: introducing novel ways of aggregating welfare into a measure of value, revising the notion of a life worth living, questioning the way we can compare and measure welfare, counting people’s welfare differently depending on the temporal location or the modal features of their lives, and challenging the logic of axiological and normative concepts. We investigate the concepts and assumptions involved in these theories as well as their implications for population theory. In our discussion, we propose a number of intuitively appealing and logically weak adequacy conditions for an acceptable population theory. Finally, we consider whether it is possible to find a theory that satisfies all of these conditions. We prove that no such theory exists. Keywords: future generations, population theory, population ethics, axiology, welfare, moral theory, social choice theory, impossibility theorems. Gustaf Arrhenius, Department of Philosophy, Uppsala University, Drottningatan 4, S-753 10 Uppsala, Sweden. © Gustaf Arrhenius 2000 Printed in Sweden by Reprocentralen Ekonomikum, Uppsala, 2000. ii For Adeze iii ACKNOWLEDGEMENTS I have received a great deal of help from a variety of individuals during the years of work that culminated in this thesis. I’ve been fortunate to have been surrounded by a group of helpful and gifted philosophers, and they have taught me the immense value of co-operation in research. To begin with, my supervisor Sven Danielsson has been very supportive – I don’t think anyone can ask for more from a supervisor. Although his detailed and trenchant criticism sometimes made me despair over the complexity of the subject and my inability to get things right, without his firm advice on how to write, or how not to write, this thesis would have been in much worse condition. I would especially like to mention his invaluable advice on how to conceptualise and structure the problems discussed in this work. My advisor, Wlodek Rabinowicz, has a special place in my career as a philosopher. Many years ago, quite bored with my studies in medicine, I strolled by the Department of Philosophy in Uppsala and decided to sign up for some courses. Wlodek was my first philosophy teacher, and his enthusiasm and inspiring lectures enticed me to leave medicine for philosophy. Later on, he was the supervisor of my Master’s thesis, and his advice and guidance during those years have made an everlasting impression on me. In a remarkably short period of time, Wlodek read the last draft of this essay, and his comments spared me many unnecessary errors. I owe my greatest intellectual debt to my friends and colleagues Krister Bykvist and Erik Carlson. I’ve been in continuous dialogue with them during the last seven years or so about philosophical questions in general, and population theory in particular. They never got tired of my confused questions, crazy proofs, and the countless of drafts of chapters with which I burdened them. They have been a constant source of intellectual challenge and philosophical comraderie. The essential part of this thesis consists of a number of theorems. I wouldn’t have succeeded in producing these without the advice of Jan Odelstad, Rysiek Sliwinski, Howard Sobel, and especially Kaj Børge Hansen. Kaj Børge took upon himself the Herculean task of checking all the theorems in this essay, and he suggested many substantial improvements. I would also like to thank Rysiek for all his help in practical matters, and for his contagious good spirit. An earlier version of a part of this thesis was successfully defended at the Department of Philosophy, University of Toronto. My thesis committee in Toronto, Wayne Sumner, Howard Sobel and Arthur Ripstein, were always willing iv to discuss not only topics from my thesis but also philosophy in general, and I’ve learned a lot from those occasions. Both Wayne and Howard continued to help me with my work after my stay in Toronto and they have read and commented in detail on several earlier versions of the present work. From Wayne, I’ve learned most of what I know about theories of welfare and much more. Howard has continuously and assiduously sent me extremely detailed and helpful comments of my work, all of which, I’m sure, I have not been able to address. The suggestions from my external examiner, Thomas Hurka, were also valuable and insightful. During my years in Toronto, I’ve benefited much from discussions with Chandra Kumar and John Gibson. Chandra has influenced my philosophical thinking far more than he can imagine. Financial support through travel grants from the Swedish Institute, The Royal Swedish Academy of Sciences, The Swedish-American Foundation, Uppsala University, and Stockholm Nation during my stay in Toronto 1994-97 is gratefully acknowledged. Over the years, I’ve discussed parts of this thesis with Thomas Anderberg, John Broome, Bruce Chapman, Danny Goldstick, Gert Helgesson, Bernard Katz, Karsten Klint Jensen, Andrew Latus, Per-Erik Malmnäs, Joshua Mozersky, Tomasz Pol, Jesper Ryberg, Peter Ryman, Pura Sanchez, Michelle Switzer, and Folke Tersman. With Jan Österberg, I’ve discussed most of the thesis and his work in population axiology has been a source of inspiration. I’m grateful to them all for the constructive criticism and the stimulating discussion they have offered. Earlier versions of parts of this thesis were presented at Svenska Filosofidagarna, Göteborg, June, 1999; “Utilitarianism Reconsidered”, ISUS, New Orleans, April 1997; “Utilitarianisme: Analyse et Histoire”, Association Charles Gide pour l'Étude de la Pensée Économique and the University of Lille, January 1996; The Learned Societies Congress, Canadian Philosophical Association, UQAM, Montreal, June 1995; the University of Copenhagen, Dept. of Philosophy, October 1997, and at the University of Calgary, Dept. of Philosophy, January 2000. I would like to thank the participants at these occasions for their stimulating criticism. The long written comments on one of my papers from Charles Blackorby, Walter Bossert, David Donaldson and from Derek Parfit were also very helpful. v Without the intellectual and emotional support of Adeze Igboemeka, I doubt that this thesis would ever have been written. Without her linguistic advice, it would have been unreadable. I dedicate this essay to her. Uppsala, April 17, 2000. Gustaf Arrhenius vi TABLE OF CONTENTS 1 INTRODUCTION.......................................................................................................................................1 2 BASIC CONCEPTS AND PRESUPPOSITIONS....................................................................................6 2.1 WELFARE AND THE VALUE OF LIFE .......................................................................................................6 2.2 ORDERINGS OF LIVES ..........................................................................................................................12 2.2.1 Comparative Ordering Presuppositions for the Adequacy Conditions .....................................13 2.2.2 Categorical Ordering Presuppositions for the Adequacy Conditions .......................................15 2.2.3 The Relation between Comparative and Categorical Welfare Statements ................................17 2.2.4 Ordering Presuppositions of Population Theories and Measurement of Welfare.....................27 2.3 THE DEFINITION OF A POPULATION .....................................................................................................33 2.4 THE DEFINITION OF A POPULATION AXIOLOGY ...................................................................................38 3 TOTAL AND AVERAGE UTILITARIANISM.....................................................................................37 3.1 TOTAL UTILITARIANISM AND THE REPUGNANT CONCLUSION .............................................................37 3.1.1 Other Things Being Equal .........................................................................................................42 3.1.2 Is the Repugnant Conclusion Unacceptable? ............................................................................45 3.1.3 Does Total Utilitarianism Imply