This book has been a long while in the making, and I have benefitted from comments and conversations in so many different settings and with so many friends, colleagues, and cordial adversaries that I will surely fail to recognize people who have helped me in the project. My sincere apologies. But the inevitability of omissions is no reason not to thank some of the people who have read or commented on all or part of the book: Larry Alexander, Jim Allan, Harriet Baber, David Brink, Luis Pereira Coutinho, Marc DeGirolami, Patrick Deneen, Mike Devitt, Ross Douthat, Brian Dunkle, Chris Eberle, Stanley Fish, Bruce Frohnen, Bill Galston, Rick Garnett, Robby George, John Inazu, Mary Keys, Andy Koppelman, Tony Kronman, Thomas LeBien, Rachel Lu, James Martin, Jennifer Newsome Martin, Susannah Monta, Michael Moreland, Michael Perry, Jeff Pojanowski, Sam Rickless, Neville Rochow, Connie Rosati, Maimon Schwarzschild, Micah Schwarztman, Merina Smith, Nathan Smith, Adrian Vermuele, William Voegeli, John Witte, Robert Wilken, and George Wright.
Discussion conferences on the book were held at Notre Dame and the University of San Diego; these were tremendously helpful. Special thanks go to Rick Garnett and Larry Alexander for organizing those conferences. At the invitation of Father Louis Caruana, I was privileged to present a distillation of several of the chapters at a conference on “La Natura e il Naturalismo” at the Pontifical Gregorian University in Rome, and I benefitted significantly from the comments and questions there. At the invitation of Brad Wilson, I had the honor of giving a much scaled-down version of the book in the Charles E. Test Lectures for the James Madison Program at Princeton. The diverse and challenging questions from the audience at those lectures were again immensely helpful.
My students Jane Susskind and John Mysliwiec provided valuable help with the footnotes and index. Arlene Penticoff assisted in preparing the manuscript, patiently enduring my use of methods and word processing programs almost as archaic as the historical developments discussed in the book.