Book excerpt: This volume deals with the reception of Aristotle's natural philosophy in Oxford between 1250 and 1270. It examines a group of ten unedited commentaries on Aristotle's Physics. This book consists of four main chapters devoted respectively to the concepts of motion, infinity, place, and time. Topics included are the question about the nature of motion, the discussion of the actual infinity in numbers, the relation between Aristotle's concepts of place in the Physics and in the Categories, the debate about the reality and the unicity of time. This book offers a comprehensive philosophical analysis of a hitherto unexplored phase of the Aristotelian natural philosophy in the Middle Ages.