WESTON JESUIT SCHOOL OF THEOLOGY LIBRARY 99 BRATTLE STREET CAMBRIDGE, MASSACHUSETTS 02138 BRITISH SOCIETY OF FRANCISCAN STUDIES VOL. IV : : : Xist of ©fffcers of tbe Society, 1912. Hon. President — Paul Sabatier. Committee — A. G. Little, Chairman. Professor T. W. Arnold. G. G. Coulton. P. Descours. Rev. W. H. Frere. T. E. Harvey, M.P. C. L. KlNGSFORD. Professor W. P. Ker, E. Moon. Rev. Canon H. Rashdall. Rev. H. G. Rosedale. Professor M. E. Sadler. Miss E. Gurney Salter. Professor T. F. Tout. Hon. Secretary and Treasurer — Mr. Paul Descours, 65 Deauville Road, Clapham Park, London, S.W. PART OF THE OPUS TERTIUM OF ROGER BACON INCLUDING A FRAGMENT NOW PRINTED FOR THE FIRST TIME EDITED BY A. G. LITTLE LIBRARY WESTON COLLEGE WESTON, MASS. ABERDEEN: THE UNIVERSITY PRESS 1912 JUL 2 1 1960 > we«ton jbuit school of theology liwarv *Z 98 BRATTLE ST. CAiASHiDGE, MASS. I21M 3£of I Q^, PREFATORY NOTE. A word is due to the members of the Society to explain the substitution of another volume on Roger Bacon for the promised volume on the Franciscans in Ireland. Father Fitzmaurice, O.F.M., who is responsible for the latter, has been appointed guardian of the Franciscan Convent at Waterford, and has had neither the leisure nor the materials for the prosecution of his historical studies. It was necessary therefore to issue something else this year ; and the discovery of an unknown frag- ment of Roger Bacon, together with the near approach of the seventh centenary of his birth (12 14- 19 14), which it is proposed to celebrate in a manner worthy of the greatest champion of experimental science in the Middle Ages, suggested the present volume. A. G. L. CONTENTS. PAGE Introduction viii Summary of the Part of the Opus Tertium here Printed ... ... ... ... ... ... xxxi Part of the Opus Tertium— De Utilitate Mathematice ad Rem Publicam dirigen- CLQrtTlt ... •• ... , # ... I De radicibus judiciorum astrologie ... ... ... 5 De locis mundi ... ... ... ... ... 9 De bonis promovendis et malis impediendis ... 13 De Perspectiva ... ... ... ... ... ... 20 De decern necessariis que ad visum requiruntur, cap. i. 24 Que sint visibilia, que in viginti duo distincta sunt, ^-dJJ, 11. •• . • ... ... ... ... 20 De particularibus modis videndi, cap. iii. ... ... 28 De bonitate videndi, cap. iiii. ... ... ... 29 De triplicibus universalibus modis videndi, cap. v. ... 30 De cognitione rei vise per sillogismum, cap. vi. ... 32 De tribus partibus perspective, cap. vii. ... ... 34 De visu facto per lineam fractam, cap. viii. ... ... 37 De comparatione scientie ad sapientiam, cap. viiii. ... 40 De Scientia Experimentorum ... ... ... ... 43 De scientia quinte essentie ... ... ... ... 47 De Morali alias Civili Scientia ... ... ... 55 De secunda parte scientie moralis ... ... ... 57 De tercia parte moralis philosophic ... ... ... 59 De quarta parte moralis philosophic ... ... 61 De quinta parte philosophie moralis ... ... 75 De Opere Minori ... ... ... ... ... JJ De Enigmatibus Alkimie ... ... ... ... 80 De expositione enigmatum alkimie . ... ... 83 De clavibus alkimie ... ... ... ... ... 86 Vll — INTRODUCTION. On 22 June, 1266, Clement IV. (who had been elected Pope on 5 February, 1265) wrote to Friar Roger called Bacon of the Order of Minors, thanking him for his letter and for the viva voce explanations furnished by " our beloved son G. called Bonecor, knight". 1 " In order (the Pope continues) that we may better understand your meaning we command you by apostolic writings, notwithstanding the precept of any prelate to the contrary or any constitution of your Order, to send to us as soon as possible a fair copy of that work which before we became Pope we asked you to communicate to our beloved son Raymond de Laon ; and to explain to us by your letter the remedies which you think advisable for the dangers which you lately pointed out ; and this you shall do without delay as secretly as you can." In answer to this command Roger Bacon composed the Opus Majus (for the Pope was wrong in thinking that the work was already written). The Opus Majus goes by various names : Opus Majus or Opus Primum or Principale in contra- distinction to the Opus Minus or Opus Secundum, and to the Opus Tertium : Tvactatus prceambulus in contradistinction to the Scripturaprincipalis or Scriptum principale, an encyclopaedic work on all the sciences which Bacon hoped to write but never completed. In the text of the work itself Bacon usually alludes to it as haec persuasio. Throughout he emphasizes the practical usefulness of knowledge in a way likely to appeal to the man of the world. The Opus Majus consists of the following seven parts of unequal length : 1 Bliss, in Cal. of Papal Registers, I., 420, reads " Bone Cornules " for " Bonecor miles ". viii — : INTRODUCTION ix I. On the causes of human ignorance. II. On the connexion of philosophy with theology. III. On the usefulness of the study of languages. IV. On the usefulness of mathematics : I. In praise of mathematics. 2-4. On physical forces and their subjection to mathe- matical laws. [5]. The application of mathematics to sacred subjects, includingJudia'a astronomiae and correctio calendarii. [6]. The application of mathematics to political matters, divided into a treatise on Geography and a treatise on Astrology. V. On the science of optics. VI. On experimental science. VII. On moral philosophy. All these are printed in Bridges' edition, except the last two (fifth and sixth) divisions of Part VII., which are missing. After finishing the Opus Majus, Bacon was induced to compose the Opus Minus by the following considerations a single work might be lost on the way the manifold (1) ; (2) occupations of the Pope made a short summary and an easier exposition of many difficulties desirable some matters ; (3) had been forgotten in the first work and might be inserted in the second ; (4) "having found remedies for earlier difficulties I could add some necessary things which I was not able to insert before " —a cryptic saying which perhaps refers to the alchemical treatises included in the Opus Minus. 1 The Opus Majus and the Opus Minus, together with the De multiplicatione specierum and a separate treatise on Alchemy, were sent to the Pope by the hand of John, Roger Bacon's favourite pupil. 2 The same reasons which led Bacon to write the Opus Minus next led him to undertake the Opus Tertium, 3 with 1 Tert., 0pus ed. Brewer, pp. 5, 42-3 ; cf. p. 77 below. 2 Ibid, pp. 3, 227, 230; ed. Duhem, pp. 164, 183 (= pp. 61, 82 below). ^Cf. Comp. Studii, ed. Brewer, p. 414.) 3 Opus. Tert., ed. Brewer, p. 67. x INTRODUCTION which we are specially concerned. Bacon was writing this in 1 1267. There 'is no evidence that it was ever sent to the Pope (who died 29 November, 1268), or indeed that it was ever finished. The Opus Tertium as edited by Brewer consists of seventy- five chapters (the division into chapters being modern). Chaps. I. -XXI. form an introduction and incorporate much of the introductory matter of the Opus Minus. Chap. XXII. summarizes Opus Majus, Part I. Chaps. XXIII.-XXIV. are concerned with Opus Majus, Part II. Chaps. XXV. -XXVI I. are concerned with Opus Majus, Part III. Chaps. XXVI II. -XXIX. is concerned with Opus Majus, Part IV., Dist. i. Chaps. are XXX. -XXXV. concerned with Opus Majusy Part IV., Dist. ii. Chap. XXVI. is concerned with Opus Majus, Part IV., Dist. iii. Chaps. XXXVII. -LII. are concerned with Opus Majus, Part IV., Dist. iv. Chaps. LIII.-LXIV. are concerned with Opus Majus, Part IV., Mathematicae in divinis utilitas (Bridges, 175-238). Chap. LXV. is concerned with Opus Majus, Part IV., Judicia Astronomiae {ibid., 238-53). Chaps. LXVI.-LXXI. are concerned with Opus Majus, Part IV., Correctio Calendarii{ibid., 269-85). Chaps. LXXII.-LXXV. deal with music and do not corres- pond to any section in Opus Majus. It will thus be seen that the Opus Tertium as edited by Brewer stopped short in its analysis of the Opus Majus, in Part IV. of that work, containing nothing on the last two sections of Part IV., and nothing on Parts V., VI. and VII. In 1909, Professor Duhem of Bordeaux published the most important Roger Bacon discovery that has been made in recent years under the title Un fragment ine'dit de I' Opus Tertium de 1 Opus Tert., ed. Brewer, pp. 277, 278. INTRODUCTION xi Roger Bacon (Quaracchi). This fragment, hidden in a MS. in the Bibliotheque Nationale 1 under the title Tertius liber Alpe- tragii, contained the summary of Part V. of the Opus Majus (including a long digression on the motions of celestial bodies), of Part VI. (in which is inserted a discussion on the halo and its relation to the rainbow), and of Part VII., including the last two unknown sections. This is followed by a brief summary of the Opus Minus, three chapters on alchemy, and finally the beginning of a treatise De rerum naturalium generatione. Professor Duhem pointed out that there still remained a gap between the end of the fragment edited by Brewer and the beginning of the fragment discovered by himself: we still lacked the summary and commentary in the Opus Tertium of the last two sections of Part IV. of the Opus Majus, those namely dealing with geography and astrology— or, as Bacon puts it, with the value of mathematics in affairs of State. The missing portion has now been discovered and is printed on pp. I -19 of this volume for the first time. The Manuscripts.— I. Winchester College MS. 39. My attention was drawn to this MS., which I had failed to note in my List of Roger Bacon's Works, by Dr. M. R. James, and I desire to thank the College authorities (and especially Mr. Hardy, the Acting Librarian, and Mr.