The editors of this volume, as well as its contributors, are particularly pleased to present this collection of essays to Professor Pierre-Marie Dupuy. The volume gathers contributions from some of the leading publicists, who are also Professor Dupuy’s friends, colleagues, and former students. The long career of Professor Dupuy, his remarkable qualities as a scholar and his deep personal influence have made it possible for many of the contributors to this volume to cumulate the three aforementioned capacities. This collection of essays marks Professor Dupuy’s retirement from his career as a teacher, but highlights also the continuity of his contribution as a writer, a practitioner and a consultant. May it be, above all, a mark of gratitude for the long-lasting contribution of Professor Pierre-Marie Dupuy to all of us!