PREFACE

THE treatises of Roger Bacon on the subject of Metaphysics Metaphysics: The branch of philosophy that examines the fundamental nature of reality, including the relationship between mind and matter. that we currently know of are the following:
1. Questions on the first [etc.] book of Metaphysics, by Master R. Bacon. original: "Questiones super primum [etc.] Methaphisice, a magistro R. Baco." (Manuscript Amiens 406, folio 74 and following, described by Cousin in the Journal des Savants, 1848, pages 459 to 472.)
2. Metaphysics of Brother Roger of the Order of Friars Minor, on the faults contracted in the study of theology. original: "Methaphisica fratris Rogeri ordinis Fratrum Minorum, de viciis contractis in studio theologie." (Manuscript Digby 190, folio 86 b, fragment; National Library 7440, folios 38 to 40 and 25 to 32, unfinished. This is the text printed in this volume.)
The names of others appear in old library lists. Three are found in the library of St. Augustine's, Canterbury, whose catalogue was published by Dr. James. These were in the possession of John of London.
3. ‘Treatise on common natural philosophy by Roger Bacon, and in the same book: Treatise on nourishment and what can be nourished by the same Roger Bacon; Treatise on the intellect and the intelligible; Treatise on sleep and waking; and the Metaphysics of the same Roger. (Second folio: and which he has.)’ 843. original: "Tractatus naturalis philosophie communis Rogeri Bacun... et Methaphisice eiusdem Rogeri."
4. ‘Metaphysics of R. Bacon in the commentary of Averroes Averroes: A 12th-century Andalusian philosopher known for his influential commentaries on Aristotle. on the book of Ethics.’ 843. original: "Methaphisice R. Bacon in commento Averois super liber Ethicorum."
5. ‘Commentary of Averroes on the book of Ethics; and in the same book: Concordance of the Ethics; Aristotle's Poetics with the commentary of Averroes; Averroes on the substance of the world; Avicenna Avicenna: An 11th-century Persian physician and philosopher who reconciled Aristotelianism with Islamic theology. on animals; Metaphysics of Roger Bacon; and Aristotle's Economics. (Second folio: in the same manner.)’ 1071. original: "Comentum Averois super librum Ethicorum... concordancie Ethicorum... poetria Aristotelis... de substantia orbis... de animalibus... Methaphisica Rogeri Bacon... Yconomica Aristotelis."
Regarding the contents of these treatises (except for the first), it is not easy to speak with any certainty. Based on Cousin's account, number 1 seems to be a scholastic treatise on questions arising from the Metaphysics of Aristotle, excluding the third and fourth books. Number 2, of which the surviving fragment is now printed for the first time, is incomplete. It gives no indication of its original length and goal. However, some grounds for a guess exist. A number of references to "my Metaphysics" occur in undisputed works of Bacon. A comparison of these will be our best guide to the contents of the lost book. The Great Work original: "Magnum Opus" (if I may name it so for now) which Bacon had been working on for years when the papal command reached him was planned to extend over four volumes (see extract 23): (1) Grammar and Logic, (2) General Principles of Mathematics, (3) General Principles of Natural Science, (4) Metaphysics and Morals. Significant portions of each of these were already written. Some of them were used in the Greater Work original: "Opus Majus" or in the Third Work original: "Opus Tertium", which was written to accompany it. Others were written later, such as parts of the General Principles of Natural Science. All of them, however, refer to the Metaphysics as already completed and well known.
The works which principally influenced Bacon in the composition of