The works collected in this volume form the true foundation of Western philosophythe base upon which Plato and Aristotle and their successors would eventually build. Yet the importance of the Pre-Socratics thinkers lies less in their influencegreat though that wasthan in their astonishing intellectual ambition and imaginative reach. Zeno’s dizzying ‘proofs’ that motion is impossible; the extraordinary atomic theories of Democritus; the haunting and enigmatic epigrams of Heraclitus; and the maxims of Alcmaeon: fragmentary as they often are, the thoughts of these philosophers seem strikingly modern in their concern to forge a truly scientific vocabulary and way of reasoning.