This two-part sourcebook gives the reader easy access to the language and thought of the Presocratic thinkers, making it possible either to read the texts continuously or to study them one by one along with commentary. It contains the complete fragments and a generous selection of testimonies for twenty major Presocratic thinkers including cosmologists, ontologists, and sophists, setting translations opposite Greek and Latin texts on facing pages to allow easy comparison. The texts are grouped in chapters by author in a mainly chronological order, each preceded by a brief introduction and an up-to-date bibliography, and followed by a brief commentary. Significant variant readings are noted. This edition contains new fragments and testimonies not included in the authoritative but now outdated Fragmente der Vorsokratiker. It is the first and only complete bilingual edition of the works of the Presocratic philosophers for English-speakers.