WORKING on this book has been largely a solo operation, but I have received some help along the way. Michelle Williams provided valuable research assistance. Arlie Hochschild and Victoria Bonnell read and commented incisively on chapter 3. Discussions with many colleagues at the National Academies of Sciences found their way into my thinking, as did questions and criticisms from audiences at presentations I made at Northern Illinois University, Illinois State University, the University of Illinois (Champaign-Urbana), the University of California, Berkeley, the University of Trento, the American Sociological Association, the Pacific Sociological Association, the National Academy of Sciences, the California Council for Science and Technology, and the Livermore National Laboratory. Jeff Robbins of the National Academies Press and Tim Sullivan of Princeton University Press saw the manuscript through various stages of preparation and production. I am also grateful to four anonymous readers for Princeton University Press, all of whom liked the book but also had many helpful things to say. I wish I could thank other assistants, administrative staff, and secretaries, but, being retired, I no longer enjoy such infrastructure. I can only congratulate myself and my computer for getting the work done.