This celebratory Festschrift dedicated to Charles Kahn comprises some 23 articles by friends, former students and colleagues, many of whom first presented their papers at the international "Presocratics and Plato" Symposium in his honor (European Cultural Center of Delphi, Greece, 3–7 June, 2009). The conference was organized and sponsored by the HYELE Institute for Comparative Studies, Parmenides Publishing, and Starcom AG, with endorsements from the International Plato Society, and the Dean of the School of Arts and Sciences, University of Pennsylvania. While Kahn's work reaches far beyond the Presocratics and Plato, it is in these subject areas that the distinction of his scholarship has come to be regarded as virtually unrivaled. The articles contributed to this volume are by some of the most renowned scholars working on these topics today, their breadth and depth bearing witness to his profound impact and influence on the discipline of Ancient Greek Philosophy.