This anthology presents the early sages of Western philosophy and science who paved the way for Plato and Aristotle and their successors. Democritus's atomic theory of matter, Zeno's dazzling "proofs" that motion is impossible, Pythagorean insights into mathematics, Heraclitus's haunting and enigmatic epigrams-all form part of a revolution in human thought that relied on reasoning, forged the first scientific vocabulary, and laid the foundations of Western philosophy. Jonathan Barnes has painstakingly brought together the surviving Presocratic fragments in their original contexts, utilizing the latest research and a newly discovered major papyrus of Empedocles.