Book excerpt: This book is a collection of papers on the metaphysics and natural philosophy of John Buridan (ca. 1295-1361), one of the most innovative and influential thinkers of the later Middle Ages. It brings together original contributions by fifteen Buridan scholars on a number of central topics in the Buridanian corpus, including the theory of universals, the role of definitions in scientific practice, necessity and probability, time, the natural order, the theory of motion, time and infinity, certitude, sensation, dreams, and volition. The papers provide a unified picture of Buridan's non-logical writings, most of which are still unedited, emphasizing throughout his particular methods of presenting and solving philosophical problems. The result suggests that Buridan's reputation for brilliance in logic and semantics deserves to be extended to other areas of philosophy, and that his work deserves closer study. Contributors include: Paul J.J.M. Bakker, Joël Biard, Dirk-Jan Dekker, Peter King, Gyula Klima, Simo Knuuttila, Gerhard Krieger, John E. Murdoch, Fabienne Pironet, Olaf Pluta, Rolf Schönberger, Peter G. Sobol, Edith Dudley Sylla, Johannes M.M.H. Thijssen, and Jack Zupko.