This collective work owes first and foremost to the commitment of all the authors of this volume. They have engaged in an intense and fruitful program of discussion and writing. It also owes to Gaëlle Gillot and Stéphane Dufoix, who accompanied us and who discussed with us the first versions of each chapter on the occasion of the authors’ seminars we organized at the Conservatoire national des arts et métiers (Paris). With their usual efficiency, Audrey Lefèvre and Zaera Mariaux offered us the necessary help to organize the authors’ seminars and publish this volume. Our research center, the Lise-CNRS-Cnam (Paris) and our colleagues have encouraged and supported this project in different ways. Thanks to Philippe Grabowksi and Sofiane Lallement, this book benefits from a magnificent cover photo. We also owe a lot to Chris Retz who did the English editing of the text and to Yamna Assoubay who checked the references and made them consistent. Finally, we are as well thankful to the team of the Brill publishing company, the editor of the collection International Comparative Social Studies, and the reviewers of the first version of this volume. They all gave us a highly valuable and constructive guidance. Thanks to all of you.