Along with my family, some friends and colleagues have been close to me while I was writing this book. Before they hear the echoes of our dialogues in the pages that follow, I wish to thank them: Ilaria, Michele, Carla, Franco, Chiara, Teresa, Nadia, Massimo, Annalisa, Giovanni, Jose, and Ian. Laura Cremonesi, Barbara Fuchs, Miriam Posner, Teo Ruiz, Silvana Seidel Menchi, and Stefania Tutino generously discussed earlier versions of this work, offering invaluable comments. I am also grateful to the anonymous reviewers and to Ralph Keen and Giorgio Caravale for their insight and for making this publication possible.