In this important collection, the editors argue that medieval philosophy is best studied as an interactive discussion between thinkers working on very much the same problems despite being often widely separated in time or place. Each section opens with at least one selection from a classical philosopher, and there are many points at which the readings chosen refer to other works that the reader will also find in this collection. There is a considerable amount of material from central figures such as Augustine, Abelard, Duns Scotus, and William of Ockham, as well as extensive texts from thinkers in the medieval Islamic world. Each selection is prefaced by a brief introduction by the editors, providing a philosophical and religious background to help make the material more accessible to the reader. This edition, updated throughout, contains a substantial new chapter on medieval psychology and philosophy of mind, with texts from authors not previously represented such as John Buridan and Peter John Olivi.