We thank all of the symposium participants for facilitating such a vibrant discussion.We wish to particularly thank Professor Don Ostrowski of Harvard University for his sage comments as we began to plan the volume, as well as the comments of the three anonymous readers who reviewed the manuscript and provided valuable feedback.Last, but not least, we are grateful to our editor, Alessandra Tosi, who has supported this volume from its earliest stages, and her team at Open Book Publishers.