This book has been a long time in the making. I have been fortunate to receive support and encouragement from many people who have helped me in various ways to complete the project. First, my good friend in Chicago, Fritz Huchting, dignified it from the beginning with the title of The Summa. My much younger colleague in Århus, Lene Kühle, kept chipping away at the initial weaknesses in one chapter. Meanwhile, Danièle Hervieu-Léger extended to me the generous hospitality and the intellectual stimulation of the Ecole des Hautes Etudes en Sciences Sociales in Paris. Further encouragement came from Françoise Champion, Jean-Paul Willaime and Véronique Altglas at the Ecole Pratique des Hautes Etudes in Paris. Finally, the Study Leave Committee of the University of Warwick supported the work at a crucial stage.

Colleagues at the University of Warwick have kept me well supplied with good ideas and entertaining distractions. Bob Jackson, Danièle Joly, Mike Neary, Eleanor Nesbitt, Jonathan Tritter, Charles Turner and Simon Williams all deserve special thanks. The genial company, embodied and electronic, of ‘the Perfect’ – Eileen Barker, Meredith McGuire, Jim Richardson, Cynthia Richardson and Jim Spickard – has been an inspiration. In addition, I am deeply appreciative of the interest in my work shown by generations of my graduate students in Chicago and Warwick and by members of the International Society for the Sociology of Religion.