This is the first great commentary in the Western European tradition of expounding Aristotle's Metaphysics. Dated about 1238, this work by Richard Rufus of Cornwall is a major contribution to the history of Western philosophy and the study of Aristotle. No future account of thirteenth-century metaphysics will be able to ignore its contribution. Rufus addresses questions as diverse as 'what is truth?', 'are there many eternal truths?', 'what is prime matter?', and 'how do corruptible and incorruptible substances differ?'. Rufus' views on the nature of truth were strongly influenced by Anselm, while his treatment of the problem of the eternal truths was influenced by his contemporary, Robert Grosseteste. But his views on prime matter owe more to his reading of Averroes and Averroes' understanding of the Aristotelian tradition, as well as to the influence of Augustine. Even so, while deeply indebted to the Aristotelian tradition, Rufus displays an independence and originality of thought throughout the Scriptum. The Scriptum's exposition of Aristotle and its exciting questions date from about 35 years before Thomas Aquinas wrote his commentary on the Metaphysics. Its publication will prompt a re-evaluation of the development of metaphysics in the Latin West. As the copious notes to this edition indicate, it was a very influential work that had a significant impact on the views of the two most popular early Aristotle commentators, Adam Buckfield and Albert the Great.