The essays in this collection represent in scholarly infrastructure to Professor Furley's major study, The Greek Cosmologists, of which volume 1 was published by the Press in 1987. They tackle the questions in ancient cosmology and the clash between the two opposing systems known as Aristotelianism and Atomism. Some essays are general reflections on the nature of the debate; others explore certain detailed questions; yet all illustrate the author's incisive approach, which cuts through irrelevancies and goes directly to the heart of an issue.