The ancient Greek philosopher Antiphon was a contemporary of Socrates who lived in the fifth century BCE Athens. Antiphon wrote several major works, which have survived only in very fragmentary form. All that is known about these works as well as about Antiphon is included in this study. The material is translated, and its significance assessed in a detailed commentary that addresses the numerous problems raised by the fragmentary material. Antiphon's contribution to the wider history of ideas is addressed in conclusion.