This book is a complete translation of the fragments of the Pre-Socratic philosophers given in Diels, Fragmente der Vorsokratiker, Fifth Edition (B-sections). Comments on readings and interpretation have been confined to footnotes, and are restricted to the minimum; for further discussion, the reader is referred to my Companion to the Pre-Socratic Philosophers, to which this book is ancillary. The fragments have been translated in full except for the longer extracts from Gorgias, which are…