The fragments and testimonia of the early Greek philosophers (often labeled the Presocratics) have always been not only a fundamental source for understanding archaic Greek culture and ancient philosophy but also a perennially fresh resource that has stimulated Western thought until the present day. This new systematic conception and presentation of the evidence differs in three ways from Hermann Diels’s groundbreaking work, as well as from later editions: it renders explicit the material’s thematic organization; it includes a selection from such related bodies of evidence as archaic poetry, classical drama, and the Hippocratic corpus; and it presents an overview of the reception of these thinkers until the end of antiquity.

Volume IX of the nine-volume Loeb edition of Early Greek Philosophy includes the so-called sophists Antiphon, Lycophron, and Xeniades, along with the Anonymous of Iamblichus, the Dissoi Logoi, a chapter on characterizations of the 'sophists' as a group, and an appendix on philosophy and philosophers in Greek drama.