I thank everyone who provided expert advice on technical matters and everyone who offered comments on the papers, book reviews, talks, interviews, and draft manuscript that eventually turned into this book. I have benefited enormously from their feedback. It not only improved the book significantly but guided the direction of my research in crucial ways. I would like to thank each one by name, but unfortunately I cannot. Even were they not too numerous to list, they include many audience members and reviewers whose names I do not know. If you are among them, please know that the difference between what you originally read or heard and the ideas.
