This book deals mainly with the decision-theoretic paradox known as ‘Newcomb's paradox’, with related examples of decision problems and with the current philosophical controversy surrounding the principle of maximizing expected utility, “causal decision theory” and such decision problems. I have taken care, in two ways, to make the book self-contained and generally accessible. First, two appendixes review the elementary logic and probability theory occasionally used; and second, the first three chapters present, somewhat in the way of a review, the more general “Bayesian” philosophical ideas and theories in relation to which the issues dealt with in the bulk of the book are philosophically significant. Also, the bibliography, though incomplete in relation to all the published work in the area, should be helpful to those interested in further pursuing the questions dealt with here.

I first became interested in these issues as a graduate student at the University of California at Berkeley. I am especially grateful to Charles Chihara, who supervised my Ph.D. dissertation, for all of his help and advice in all aspects and stages of the development of that project, out of which this book has arisen, and for his continued interest and advice. I have also benefited from discussions with Ernest Adams. Discussions with Brian Skyrms inspired many and corrected many of my views on his theory of K-expectation. I have had the benefit of discussing the ideas of Chapter 6 at talks given at the University of Chicago, North Carolina State University at Raleigh, the University of Wisconsin at Milwaukee, the University of Illinois at Chicago Circle, State University of New York at Buffalo and the University of Wisconsin at Madison. Richard Jeffrey and David Lewis have offered helpful comments and supplied me with useful pre-publication manuscripts dealing with the relevant issues. I am also indebted to N. A. Blue, James H. Fetzer, Morry Lipson and especially D. H. Mellor, editor of the series, for many helpful and strategic suggestions in connection with the introductory chapters.