Commentary on Aristotle's Metaphysics

TRANSLATED BY

JOHN P. ROWAN

PROFESSOR OF PHILOSOPHY

DUQUESNE UNIVERSITY

Library of Living Catholic Thought

VOLUME I

HENRY REGNERY COMPANY

Chicago 1961

Manufactured in the United States of America

Library of Congress Catalog Card Number 61-16878

CONTENTS

VOLUME I

Introduction

Prologue of St. Thomas

Book

I ({A}) Introduction to First Philosophy. History of Metaphysical Inquiry

II ({a}) The Search for Truth and Causes

III ({B}) Metaphysical Problems

IV ({G}) Being and First Principles

V ({D}) Lexicon of Philosophical Terms

List of Works Cited

VOLUME II

VI ({E}) The Scope of Metaphysics

VII ({Z} Substance, Essence and Definition

VIII ({E}) The Principles of Sensible Substances: Matter and Form

IX ({Th}) Actuality and Potentiality

X ({I}) Unity

XI ({K}) Recapitulation on the Nature and Subject of Metaphysics. Motion

XII ({L}) Mobile and Immobile Substance. The Prime Mover

List of Works Cited

INTRODUCTION

I--THE TRANSLATION

The following translation of St. Thomas' Commentary on the Metaphysics of Aristotle includes a translation of the version of Aristotle's text that is found in the printed editions of the Commentary now in use and commonly thought to be the one employed by St. Thomas. The inclusion of a translation of this version appeared necessary from the very beginning for two reasons. First, since the Commentary is a detailed analysis and exposition of the text of Aristotle, it becomes fully intelligible only in relation to the text, to which it makes constant reference as its point of departure. Second, since the version frequently departs in some measure from the original, it would not have proved feasible to employ one of the modern English translations based on the Greek.

The translation both of the Commentary and of the version of Aristotle is based on the edition of Raymund M. Spiazzi, O.P. This edition is fundamentally that of M. R. Cathala, O.P., with emendations. Some assistance in clearing up obscurities, such as typographical errors and the like, was obtained by consulting the edition of Parma and that of Vivès. However, the usefulness of these editions in this regard proved to be limited inasmuch as both the edition of Vivès and that of Cathala use Parma as their basic text.

Since the Cathala-Spiazzi edition is not a critical one, it was necessary in certain instances to alter the reading of the text. Where such alterations are made and are not obvious, they are indicated in a footnote, and the reason for making them is stated when such justification appears necessary. The more important variations between the Greek text as given in Bekker and the Latin version of Aristotle's text are also indicated in footnotes. If the reader wishes to make comparisons between the version, the Greek text, and the English translations, he will find the Bekker reference numbers given at the beginning of each lesson useful in locating the passages in which he is interested.

The translation does not pretend to be a transliteration of the original. Since strict adherence to this method very often results in the use of latinisms and word structures that are foreign to the English reader, it seemed advisable, if the thought of the original was to be presented in as accurate and readily understandable a form as possible, to render the Latin as idiomatically and meaningfully as current English usage permits. Where the English words and phrases used to translate technical Latin terms are not those commonly employed in presenting the thought of St. Thomas and of Aristotle, the reader will find this indicated either by a footnote or by giving the Latin in parenthesis after the word or phrase in question. Throughout the whole translation the aim has been to produce as faithful and accurate a rendition of St. Thomas' work as circumstances permit. The extent to which this has been achieved will be left for the critics to decide.

The reader will find that the form of the introductory statements customarily used by St. Thomas to designate the passages of Aristotle's text which he is about to explain, has been abbreviated. This has been done to avoid repetition and simplify the reading; for example, such statements as, "Then when Aristotle says, 'Animals by nature (2) . . . ," and, "Then when he says, 'Furthermore, it is necessary (126) . . . ," have been shortened to read, "Animals by nature (2)," and "Furthermore, it is necessary (126)."

The sections of the Commentary are indicated by numbers preceded by C, and are the same as those originally established by Cathala. Numbers not preceded by C designate the sections of the version of Aristotle, and are identical with those given by Spiazzi in his revision of the Cathala edition. The use of such numbers, singly or in combination, throughout the text, simplifies the matter of references and cross references where such are specified by the author, or where they would otherwise seem to be helpful. Thus in the case (267:C 489) the first number designates the section of the version of Aristotle, and the second, the section of St. Thomas' Commentary on this passage.

II--THE NATURE OF THE COMMENTARY

A commentary or exposition of the thought of some writer constituted one of the basic methods of teaching employed in medieval schools. Medieval writers inherited the commentary as a pedagogical instrument from two sources, the Fathers and Arabic writers, both of whom adopted it in turn from a common source--the literary and scientific writings of the last period of Greek thought. In the West the commentary took various forms. One type which appears as early as the sixth century is that employed by Boethius in certain of his writings, for example, his expositions of the Categories and the De Interpretatione of Aristotle. Here a portion of the original text in translation is given first, and then an explanation of its content in simpler form. Glosses upon a text constituted another form of commentary, and this became a popular form of exposition from the ninth to the twelfth century. During the twelfth and thirteenth centuries the West was introduced to the thought of antiquity by way of translations from the Greek and the Arabic. The latter were more numerous and presumably the first to appear, and it was through them that Europe first came in contact with a large part of Aristotle's thought of which it had heretofore been ignorant. While there is ample evidence that these early translations extended to certain of Aristotle's works, and the Metaphysics was one of these, the translations for the most part were of summaries or paraphrases of his writings, such as those composed by Alfarabi and Algazel, and especially the Kitâb assifâ of Avicenna, which is his principal work and a sort of philosophic encyclopedia covering the fields of logic, physics, metaphysics and mathematics. The method of paraphrasing was imitated by Latin writers since it provided a simple means of presenting and popularizing Aristotle's views. St. Albert the Great, for example, made an extensive use of it in his "adapting Aristotle for the use of the Latin races."

In addition to the paraphrase the West was also introduced to a more technical form of commentary, a more systematic method of analysis and explanation, which came to be known as the lectio, and was so named because it consisted fundamentally of a number of readings or lessons (lectiones) of the text of an authority, accompanied by a literal explanation. This method of procedure, the literal commentary, eventually took precedence over the other forms of exposition and came to be widely used during the thirteenth and fourteenth centuries. Its originator is Averroes (The Commentator), who utilized it in what are called his "major commentaries." In these the text of Aristotle is given paragraph by paragraph, and the views, intentions and expressions of the author exposed in detail.

Considering the importance of Aristotle for the West, and the need for a true understanding of his thought, it is not surprising that St. Thomas should have adopted the method of literally commenting upon his writings in preference to the procedure of paraphrasing, which had previously been used. He adopted it as "a new way of treating the text," as Ptolemy of Lucca points out, because it provided him with the best critical instrument for keeping in contact with the original and interpreting it accurately. The influence of Averroes upon St. Thomas in his commentaries generally, and in his exposition of the Metaphysics in particular, cannot be denied; and many interesting comparisons can be drawn between the expositions of the two men; for example, even in the matter of the divisions of the text into lessons, St. Thomas is evidently following The Commentator.

While it is clear that St. Thomas' primary aim is to explain literally what Aristotle said, it should also be noted that, in keeping with his respect for authority, he does not hesitate to "interpret" Aristotle, when the occasion demands. Attention must be drawn also to the fact that, since St. Thomas is principally concerned with the advancement of truth, he sometimes proceeds to draw out what he feels is implicit in Aristotle's doctrines. In so doing he introduces his own personal views into his explanations inasmuch as he sees a fundamental agreement between them and those of the Philosopher. In the same spirit he sometimes finds it necessary to disagree with the interpretations of other commentators, chiefly those of Avicenna and of Averroes, when he feels that they fail to grasp the thought of the master on some specific point of doctrine. But he can also use the opinions of those whom he has criticised in other respects, when it is evident that their interpretations add something to the understanding of Aristotle's teachings.

In his role as commentator St. Thomas makes a masterful use, both of the many dialectical instruments which Aristotle puts at the disposal of his readers in his methodological treatises, as well as of those developed by medieval logicians. In this respect alone the Commentary is an outstanding piece of work. Since Aristotle's text is fundamentally an inquiry or investigation into problems relevant to a specific subject matter, conducted along the lines recommended in the Analytics and Topics, it lends itself admirably to the kind of treatment to which St. Thomas subjects it. Aristotle's text might be described as an exercise in dialectic aimed at ascertaining truth in a certain sphere, and whose logical structure the reader is aware of only vaguely if at all. But in the treatment of the Commentary this structure is laid bare in order to better evaluate the conclusions to which it leads. For the medievals as for Aristotle a knowledge of method provided at once both the tools necessary for scientific research and the criteria, in large part at least, for judging the value of such research.

With this in mind St. Thomas proceeds from the very start to make evident with great precision both the content of Aristotle's thought and the process which he uses in formulating and presenting it. He divides and subdivides the text to reveal its essential structure, and within these divisions he follows step by step Aristotle's analyses of his predecessor's opinions and his evaluation of them; his examination of the various meanings of terms; the kind of arguments that are being used, and their demonstrative or probable character in the light of the premises from which they are derived.

The divisions of the text, which are given in the Commentary at the beginning of each lesson, serve to break up the passages to be commented upon into their constituent parts or members, thereby presenting the student with a schema that enables him to proceed in an orderly way to an understanding of the discussion contained therein. Sometimes the divisions given in one lesson will extend to subsequent lessons when the latter have an essential connection with it. There are also cases where the division extends to the work at large, indicating the issues dealt with in other books. Thus in Book III, after explaining the aporiae or difficulties which Aristotle raises, St. Thomas notes the respective books in which they will be solved; and again in Book XI, lesson 1, his division refers not only to certain issues that have yet to be treated, and where this will occur, but also designates topics that have already been discussed in previous books.

In his treatment of the text St. Thomas exhibits none of the critical and historical spirit that is so characteristic of our own era and began with the advances in philological studies and historical methodology made in the nineteenth century. This does not mean that he is lacking in historical sense or in critical ability (quite the reverse is true), but that he does not have at his disposal the variety of instruments in these fields that we now possess. His only method of ascertaining the true sense of Aristotle's text was to consult the various versions available to him. If he saw any development in Aristotle's thought, such as might be suggested by the text, and of the kind outlined in the works of modern scholars, he gives no indication of it. Neither does he remark on the possibility of the various books which comprise the total work having been composed as distinct treatises at different times and combined into a whole by later hands. For him the work has the appearance of a single treatise whose parts have been skilfully knit together with the ultimate aim of exposing the nature of entity, its properties and causes.

III--RESEARCHES ON THE COMMENTARY

The most important issues with which scholars have been concerned in the matter of the Commentary are (1) the period of its composition and date of completion; (2) the version or versions upon which St. Thomas based his exegesis, and the exact status of the printed version now in use; (3) the history of certain of the books commented upon, and the possibility of an earlier and later writing. These issues have been investigated at length, and much progress has been made despite the obstacles that have had to be faced. However, the tentative character of many of the solutions proposed for them indicates that considerable work yet remains to be done.

One of the main obstacles in the way of attaining definitive answers is the state of the printed editions and the manuscripts of this work with which investigators have had to deal. Both are admittedly imperfect, containing errors of various kinds. It is quite possible too that the manuscripts representing the versions of Aristotle's text which St. Thomas used in his exposition are not yet completely known. There is also the matter of the interpretation which should be given to the passages in various works which refer in some way to the Commentary or to the versions of Aristotle, and have been used as evidence by one or other investigator in support of his position regarding some phase of this work. These passages are often obscure, ambiguous and perhaps even inaccurate, and so have led in many instances to different and even contradictory hypotheses.

Although little if anything has been published on the errors to be found in the manuscripts, sufficient information is at hand regarding the kind of inaccuracies one can expect to meet in the printed editions, and the reasons for their occurrence. In this matter one can cite the brief article of A. Mansion, dealing with the Commentaries on the Physics and Metaphysics, and the article of L. W. Keeler, S.J., which, while it deals specifically with one of the Opuscula of St. Thomas, is nevertheless of importance for the Commentary on the Metaphysics.

Mansion draws attention to the role that simple negligence has played in falsifying the text of the Commentary, and uses as an example a passage at the beginning of Book I, corresponding to Bekker 980a 27-28, which, rendered into Latin, reads, "Animalia quidem igitur natura sensum habentia fiunt." The phrase, as he points out, is given in the editions of Venice 1519, Rome 1570, Venice 1603, and Antwerp 1612, but is omitted in the edition of Parma 1866, and therefore also in the edition of Vivès 1889 and in that of Cathala 1915 (although corrected in the 1926 and following editions), since both of the latter employ Parma as their basic text without any apparent revision. Mansion's conclusion is that in all probability there are many other such errors in the printed editions (which has been borne out by more recent studies), and that an examination of the manuscripts upon which these editions have been based will reveal inaccuracies of a similar kind.

Father Keeler's work reveals another and different kind of error in his descriptions of the procedures followed by the editors of the sixteenth century, whose editions have been employed in printings down to our own time. The outstanding weakness of early editors, he notes, consisted in their "undue readiness" to take all sorts of liberties with the text. Thus Paulus Soncinas did not hesitate to substitute certain passages from humanist translations of Aristotle's text for those in medieval Latin when the latter appeared obscure or were too strange or archaic to suit his taste. Thus in the case of St. Thomas' exposition of the De Generatione Animalium of Aristotle, Soncinas substituted passages of the nova translatio of this work for certain parts of the media translatio, which seems to have been the one that St. Thomas employed. The same kind of procedure is also characteristic of the work of Anthony Pizamanus, who, in his edition of the De Unitate Intellectus, is responsible for what Keeler calls the "scandal" connected with St. Thomas' supposed assertion that he had seen certain books of Aristotle, fourteen in number, which treat of separate substances but had not yet been translated into Latin (presumably the fourteen books of the Metaphysics). Keeler's researches reveal that there are no manuscripts that contain the reading numero XIV, but that all having a numerical reference read numero X, while one (St. Genevieve 238) omits the words in question altogether. Apparently Pizamanus, who was following an earlier edition of Soncinas, which omits any mention of the number of books, considered this a lacuna and supplied the reading numero XIV on the basis of a reading found in another edition of this work prepared by a certain Didascalus, which edition he was also following. The issue is significant for the history of the Commentary inasmuch as one thesis of D. Salman, O.P., an investigator in this field, depends on the assumption that the reading numero XIV is correct.

Difficulties of this kind will disappear only when critical editions have been made of all of St. Thomas' writings. In the meantime they will continue to make the undertaking of translation and historical investigation extremely difficult.

1. The Date of the Commentary

The extensive researches that have been made into the history and chronology of St. Thomas' writings would indicate that the commentaries on Aristotle were composed between the years 1266-1272. Some were at least begun while St. Thomas resided in Italy, and some were completed at Paris after his return there to teach for the second time. The Commentary on the Metaphysics is generally considered to belong to this second group. However, while there seems to be agreement as to the proximate date of its completion, both the time and place of its origin still remains a matter of dispute. One can appreciate the complexity of the problem and the tentative character of many of the solutions proposed for it only by surveying the studies that have been made.

One of the earliest dates given for the composition of the Commentary is that found in the account of St. Thomas' life and writings by Ptolemy of Lucca, who ascribes it to the pontificate of Urban IV. According to Ptolemy, St. Thomas commented during this period upon the whole of philosophy, both moral and natural, and "especially upon the Ethics and Metaphysics." This would mean that the Commentary was written between 1261 and 1264. Ptolemy's authority in this matter has been questioned by M. Grabmann because of a discrepancy in the dates involved, inasmuch as St. Thomas resided at Rome from 1265 to 1267, whereas Urban IV reigned from 1261 to 1264. However, P. Mandonnet has argued in favor of Ptolemy's statement on the grounds that, since one of these periods immediately succeeds the other, and since St. Thomas did teach at the court of Urban IV at Orvieto, which is adjacent to Rome, Ptolemy was very likely thinking of the whole period from 1261 to 1267.

As early as 1921 Grabmann expressed the view that the Commentary could not have been completed before 1265, the date set earlier by Mandonnet, but must have been in the process of composition during 1266. His opinion was based on a reference which St. Thomas makes in Book III, lesson 11 (C 468) to Simplicius' Commentary on the Categories of Aristotle, the translation of which was only completed by William of Moerbeke in March 1266, and was the one available to St. Thomas.

In 1925 A. Mansion published his findings to the effect that the work could not have been completed before 1271, but must have reached its final state toward the end of that year or at the beginning of 1272. His decision was based on the date of the translation of Simplicius' Commentary on the De Coelo of Aristotle, which was completed by Moerbeke in June 1271. St. Thomas makes three references to this work in Book XII of the Commentary when he sets out to explain the use that Aristotle made of Eudoxus and Calippus in the formation of his astronomical system. Two of these references are paraphrases (C 2573; C 2582), and one is an exact citation (C 2578), and this would have been possible only if he had possessed the translation at the time of writing.

In 1942 T. Deman published his researches on St. Thomas' opinion of Aristotle as an interpreter of Plato, and indicated in this article that the reference to Simplicius' Commentary on the Categories, given in Book III of St. Thomas' Commentary, appeared rather to be a reference to Simplicius' Commentary on the De Coelo. This conclusion, contrary to that reached earlier by Grabmann, would necessitate putting the writing of Book III sometime after June 1271. But granted that this were the case, it would follow that St. Thomas must have composed the whole of his exposition in a much shorter period than the many demands on his time as teacher, scholar and writer would reasonably allow. This has been the view expressed by D. Salman, and on the basis of this and what he considers to be internal evidence supplied by the Commentary and by other writings of St. Thomas, he argues in favor of an earlier writing composed in Italy between 1266 and 1268, and a revision of this made later at Paris between the end of 1270 and the beginning of 1272. He also thinks that Ptolemy's account could simply refer to such a first writing, and that this might have taken the form of a simple reportatio. In his opinion the argument for an earlier writing is not invalidated by the evidence summoned in support of a later period of composition, for example, the reference made to Simplicius in Book III, and the mentioning of Books XIII and XIV of Aristotle's work as early as the exposition of Book I, since these could have been added later at the time of revision. In this matter Salman is in agreement with the view expressed earlier by Mansion, and also with that of A. Dondaine, O.P., although the latter's argument for an earlier date of composition was based on the assumption that the translatio media constituted the basic text upon which the Commentary was made, and that the translatio nova was employed later when the work was revised.

The researches of F. Pelster, S.J., which have been aimed primarily at establishing the version or versions of Aristotle's text that were used by St. Thomas, deserves special attention in regard to the present problem. Pelster's findings agree with those of other scholars as to the proximate time of completion of the Commentary; and while he admits that the hypothesis of an earlier writing is not impossible, he thinks that such a hypothesis is unnecessary, since what is used as evidence in support of it can be explained in another way, as will be noted later.

From such investigations, then, it appears probable that the Commentary was completed at Paris towards the end of 1271 or at the beginning of 1272, but that the time and place of its origin are still not definitely known. It seems possible that it could have been written in its entirety during St. Thomas' last period at Paris; or that it was begun during his stay in Italy and completed at Paris as a single writing; or that a first writing was composed in Italy, and this subsequently revised at Paris.

2. The Versions on Which the Commentary Is Based

In order to give an accurate exposition of the true thought of Aristotle, St. Thomas required a faithful version of the original texts as a basis for his commentaries. The various paraphrases then in vogue could, therefore, hardly serve his purpose. Being merely summaries they neither contained the actual text of Aristotle nor pretended to follow the original order of exposition, but employed instead a simpler and more systematic one established by the summarists themselves. Moreover, they frequently incorporated the views of their composers, views that sometimes made the Philosopher the exponent of doctrines that were often difficult if not impossible to reconcile with the principles of Christian wisdom. In view of the possibility that Aristotle himself might have something quite different to say, prudence dictated the exclusion of such paraphrases as the starting point for a satisfactory exposition.

The translation of certain of Aristotle's works made from the Arabic also proved to have serious defects, and therefore were useful only in a limited way as a point of departure for the exegetical work St. Thomas had in mind. This at least was true of the translation of the Metaphysics, which he reputedly knew from the very beginning of his literary career. For one thing it was clearly inadequate inasmuch as it lacked Books XI, XIII and XIV, and contained only a garbled version of Books I ({A}) and II ({a})--Book I being comprised of Book {a} and part of Book {A} (chapters 5 and 8), and Book II of the remainder of Book A. The possibility too of such translations misrepresenting the thought of Aristotle had already been recognized and indicated in the pronouncements prohibiting their use on the part of the Masters and students at the University of Paris, as set forth in the earlier decrees of 1210 and 1215, mentioned above, and in the later decree of 1263. That these versions should be held suspect is not to be wondered at considering the fact that the original works had undergone successive translations from the Greek to the Syriac, from this to the Arabic, and from this again to the Latin through some vernacular language.

Somewhat the same situation prevailed in the case of certain translations of the Metaphysics that were presumably based on the Greek and date from the end of the twelfth or the early years of the thirteenth century. The translation attributed to Boethius (the littera Boethii) and another entitled the translatio vetus belong to this group. Both of these are incomplete, containing only a small part of the whole.

If the commentaries were to do justice to the real thought of Aristotle, it became evident that they would have to be based on complete and faithful translations made from the original; and so it was, as William of Tocco tells us, that, when St. Thomas wrote his expositions on natural philosophy, moral philosophy and metaphysics, "he had these books newly translated so that the genuine thought of Aristotle should be more clearly expressed." The translations of which William of Tocco speaks are those of William of Moerbeke, made at the request of St. Thomas himself. For the role that Moerbeke played as Greek translator, and the invaluable assistance that he lent St. Thomas and others in their own work, one can profitably consult the work of M. Grabmann, Guglielmo di Moerbeke, O.P., Il Traduttore delle Opere di Aristotele (Rome, 1946). In the matter of the translations of Aristotle, Moerbeke made, in certain instances, a revision of already existing versions, completing them where necessary, and also rendered into Latin certain texts that had not yet been translated. With such works in his possession St. Thomas was able to attain a knowledge of Aristotle superior to that of his predecessors and contemporaries, and give the first faithful explication of his doctrines.

Granted that certain versions of the Metaphysics anteceded that of Moerbeke and were known to St. Thomas, the following questions have been raised by scholars in their investigations into the history of his Commentary on this work: Did St. Thomas base his exegesis solely upon the translation of Moerbeke, or did he also make use of these other versions? And if the latter, what versions were involved, and to what extent? Again, is the version of Aristotle now found in the printed editions of the Commentary to be identified with the translation of Moerbeke?

In regard to the version referred to in this last question, some clarification is necessary. As indicated earlier, the printed editions of the Commentary now in use are, for the most part, republications of editions dating from the sixteenth century. In some of these, for example the Parma, one finds at the beginning of each lesson two parallel versions. One is called the versio antiqua, and the other the versio recens. Since the latter is attributable to Cardinal Bessarion, a humanist of the Renaissance period, it has no bearing on St. Thomas' own work, and therefore is excluded from the present discussion. The versio antiqua, on the other hand, is presumably the version of William of Moerbeke, and therefore the one employed by St. Thomas.

Although some of the studies devoted to finding solutions for these questions have not always been in agreement in terms of their results, it would nevertheless appear that we are now in a fair position to understand what actually occurred in the matter of the various versions.

In an article published in 1932, D. Salman outlines for us, by way of an introduction to the results of his own investigations, the discoveries of four scholars who have been chiefly responsible up to his own time for the progress made in the matter of the Latin translations used in the composition of the Commentary. First, there is the work of Monsignor Grabmann, whose researches revealed two manuscripts containing two distinct versions of the Metaphysics. One of these, which came to be called the translatio nova, was complete, while the other, which was entitled the metaphysica vetus or translatio vetus, was not, but contained only the first three books and a part of Book IV (up to 1007a 30). The latter was considered to be the work of Boethius, and the former was identified as that of Moerbeke.

In 1917 there appeared a work by B. Geyer which was devoted to a study of the citations from the Metaphysics as given in the works of St. Albert the Great and St. Thomas. By comparing the citations of St. Thomas drawn from a work which he referred to as the littera Boethii with the corresponding passages in the vetus, Geyer concluded that they were one and the same text. Moreover, since St. Thomas refers to the littera Boethii even for passages drawn from Books V and XII, Geyer also concluded that this translation, and therefore the vetus, which he identified with it, must go as far as Book XII rather than terminate with Book IV. Additional researches, however, have not fulfilled his hope of discovering the whole text. In fact the studies of F. Pelster, published in 1923, revealed eight new manuscripts all terminating in Book IV, which would seem to indicate that the original version itself was incomplete and had undergone a number of revisions. But since this conclusion fails to account for St. Thomas' references to later books of the littera Boethii, Geyer's identification of this version with the vetus was considered to be untenable.

The main contribution to this issue made by Pelster in this early study consisted in the discovery of two manuscripts containing a heretofore unknown version in thirteen books (XI being excluded), which he named the translatio media. By comparing the citations from the Metaphysics in the Summa Contra Gentiles with the corresponding passages in the media, Pelster concluded that it was this version that St. Thomas had used, and that it must therefore have been known in 1260. This being so, it would have provided one source for the writing of the Commentary, and later investigations proved this to be true. Pelster also indicated that this text was the same as that known and used by St. Albert the Great in his paraphrase of the Metaphysics, which contains thirteen books, one corresponding to each of the books in question. Since comparisons also revealed that this version differed widely from the vetus but came very close to the translatio nova, identified as the work of Moerbeke, Pelster therefore decided that Moerbeke had employed the media in composing his own translation, retouching it where necessary in the light of the Greek text, and completing it by translating Book XI into Latin for the first time.

In a subsequent study, published in 1928, M. Birkenmajer added to the complexity of the problem by introducing still another version, whose existence he supported by three new manuscripts that he had discovered. This version, whose date he placed around the middle of the twelfth century, would be older than any of the others, and therefore was called by him the vetustissima. It resembled the littera Boethii and the vetus in being composed of the first three books and a part of the fourth. The media he dated earlier than Pelster, maintaining that it was in circulation as early as 1230 or even 1210, although he agreed with Pelster on the nova as the work of Moerbeke. The vetus he considered to be a reworking of the vetustissima in the light of the media.

To the work of his predecessors Salman adds the results of his own researches to the effect that, if the facts were to be adequately accounted for, it would appear necessary to admit the existence of yet another translation, which would come between the vetustissima and the media, and would lack Books XI, XIII and XIV. In his opinion it would be upon this text rather than the media that St. Thomas relied in composing his first writing of the Commentary, since the media could not have been known as early as 1230 as Birkenmajer had claimed, or even as early as 1260 as Pelster had maintained.

Salman's argument for a later dating of the media is based upon certain passages in some of St. Thomas' works. According to him these passages indicate that St. Thomas came to know the last books of the Metaphysics only in the very last years of his career; and this being so, the media could not have been known or used by him, since it contained the books in question. The passages referred to are those in which St. Thomas speaks of a treatise of Aristotle on separate substances, belonging to the realm of metaphysics, and which Salman identifies, on the strength of the reading in the De Unitate, with Books XIII and XIV of the Metaphysics. In his opinion these books could not have reached St. Thomas before the later part of 1270. Indeed, according to the passage in the Commentary on the De Anima, Book III, lesson 12 (n. 785), at the time of its composition (after 1266), St. Thomas was not even certain that such a treatise had ever been written; but he states categorically that it was still unknown in the West. The passages from the Commentary on the De Sensu, lesson 1 (n. 4) (dated after 1261), the De Veritate, q. 18, art. 5, obj. 8 and ans. (dated the beginning of 1258), and the Quaestio Disputata de Anima, art. 16 (dated the beginning of 1270), also bear witness to his ignorance of this treatise. However, by the time of writing of the De Unitate Intellectus (dated 1270) St. Thomas knew that such a treatise actually existed, having seen the Greek text, and that it brought the total number of books up to fourteen, but that it had not yet been translated into Latin. The passage from the De Unitate to which Salman refers in support of his interpretation runs thus: "Hujusmodi autem quaestiones certissime colligi potest Aristotelem solvisse in his libros quos patet eum scripsisse de substantiis separatis, ex his quae dicit in principio XII Metaphysicae, quos etiam libros vidimus numero XIV, licet nondum translatos in linguam nostram." Assuming, then, that St. Thomas did not know Books XIII and XIV until 1270, and that these books were presented for the first time in the media, he could not have employed this version in the first writing of the Commentary, which was composed, in Salman's opinion, during the period of his career in Italy. But neither could he have depended solely upon the vetus or littera Boethii, since these versions go only as far as Book IV, whereas the first writing must have covered all books with the exception of XI, XIII and XIV. Some other version therefore must have been available to him, and it would have to contain eleven books (I-X and XII).

According to Salman this version would be a combination of the vetustissima and an early translation based on the Arabic--one version making up for the deficiencies of the other. The existence of such a translation, he notes, is attested to by a document published by Lacombe, which describes three translations of the Metaphysics done at different times: a first or early version that was incomplete (which Salman identifies with the vetustissima); a second and later translation which is clearly identifiable with the Arabic by reason of its lacking Books XI, XIII and XIV, and the confusion of the first two books; and a third and still later translation containing thirteen books (which Salman presumably identifies as the media). Since this new version which Salman proposes as the foundation for St. Thomas' work would depend predominantly on the second translation, he named it the metaphysica secunda.

However, Salman's argument appears to have lost most if not all of its force in the light of the investigations of Keeler and the extensive studies of Pelster. If the reading numero XIV of the De Unitate Intellectus cannot be substantiated by any documentary evidence other than the faulty edition of Pizamanus, as Keeler has apparently shown (since most manuscripts contain the reading numero X, while others make no specific mention of the number of books at all), it would seem reasonable to maintain, as Pelster has done, that the work to which St. Thomas alludes in the passages singled out by Salman, might be the Theology of Aristotle (an apocryphal work in ten parts) or some other work which Aristotle is supposed to have written on separate substances. This interpretation, however, does not appear to be confirmed by any positive evidence, and Salman himself has rejected it on the ground that, since the Theology of Aristotle is generally admitted to have been in circulation in the West as early as the beginning of the thirteenth century, and would thus be known to St. Thomas, it can hardly be the treatise to which he refers.

The researches of Pelster, published in 1935 and 1936, are of special significance for the present problem. His conclusions are based on an extensive study of the manuscripts of the various versions, and in this undertaking he has made great use of the collection of texts assembled earlier by Geyer. By comparing the citations from the Metaphysics that St. Thomas gives throughout his works at large, and the direct references that he makes to the text of Aristotle in his exposition of the Metaphysics, with the corresponding passages in the various versions, Pelster has been able to identify the translations that St. Thomas knew and used during his literary career. As a result of such studies he has concluded that St. Thomas knew the metaphysica vetus and the translation based on the Arabic from the very beginning of his career, and that, while he unquestionably employed the vetus in various works, he does not appear to have made any use of the translation from the Arabic (at least not in the Commentary); the littera Boethii, which for St. Thomas went beyond Book IV, is taken, not from the metaphysica vetustissima, but from the translatio vetus, so that the latter version and that of the littera Boethii are different; St. Thomas knew the metaphysica nova when he wrote the De Unitate Intellectus in 1270, and also when he composed the first part of the Summa Theologiae, shortly after 1265, since both of these works contain citations from this version; St. Thomas both knew and used the translatio media in the De Unitate Intellectus and in the Summa Contra Gentiles, composed about 1260, and probably also in the De Veritate, as some passages would seem to indicate. There are of course some references which it is impossible or difficult to identify either with the nova or the media, since St. Thomas sometimes gives Aristotle's thought only in digested form.

It is in identifying the sources to which St. Thomas refers throughout the Commentary that the versions used in its composition become evident. According to Pelster's investigations these texts are evidently the vetus, littera Boethii, media and nova, and presumably another translation based on the Greek, that went beyond Book IV, unless the readings indicative of its existence are merely variants of the media and the nova, as could be the case. The undertaking has not been an easy one inasmuch as St. Thomas refers to the various versions which he is using simply as "this reading" (haec littera) when they constitute the basic text or first reading on which he is depending, and as "another reading" or "another translation" (alia littera or alia translatio) when they fill the role of a secondary text or alternate reading. It is only in the case of the text attributed to Boethius that his source is clearly designated.

Generally it can be said that it was by reason of the clarity of its presentation (and this established by comparison) that one of these versions was given precedence over the others as the basic reading to be followed; and since this varied from version to version in relation to the particular book or chapter that was being considered, it became necessary to change the basic reading. In this way a version that constituted a primary reading in some parts became a secondary or alternate reading in others, its place being taken by one that had previously been secondary.

Pelster's conclusions given in summary form amount to the following: from Books I to IV St. Thomas constantly used the vetus and the media, and often gave first place to the former, as in Book II, lesson 2, and Book IV, lesson 5. In Book V the media appears to be the basic text, and beginning with lesson 20 of this book the nova appears for the first time as "another reading," although sometimes the vetus can be understood in this role. It would seem too that St. Thomas knew the nova as early as the writing of Book I; but since the vetus and the nova have the same reading, it is difficult to decide in favor of the nova. While the nova cannot be shown to be the fundamental reading for the first five books, there is every indication that by the time of writing of Book VI St. Thomas began to make greater use of it as his point of departure, and often does this without taking the media into account at all. In the matter of the divisions that are given for the text of Aristotle, the media appears to have been used as an aid, and St. Thomas probably also derives from it the Greek words which are translated along with the nova. Sometimes, however, the vetus is preferred to the media in the establishing of these divisions. After Book IX St. Thomas appears to have relied solely upon the nova, since no alternate readings are given thereafter. The versio antiqua given in the printed editions is not simply the nova of Moerbeke, but a mixed form of the nova and media.

Having established the foregoing, Pelster feels justified in dismissing Dondaine's opinion that the media constituted the basic text for St. Thomas' exposition, while the nova was used later only in a revisory capacity. Such a hypothesis is inadmissible in view of the position that the nova holds in the later books. Salman's assumption of a metaphysica secunda is similarly untenable inasmuch as St. Thomas was fully acquainted with the media, as numerous comparisons have shown.

3. The Problem of the Last Books

One of the central problems which scholars have had to face in their investigations into the history of the Commentary concerns the last books of the Metaphysics, specifically Books XI, XIII and XIV. Were they available or not to St. Thomas when he began his exposition? Some have felt that they were, while others have adopted the opposite position, maintaining that he came to know and use them only at a later date.

The doxology that St. Thomas gives at the end of Book XII seems to clearly indicate that he considered his work to be completed at this point. In this respect the Commentary on the Metaphysics is unique, as Mansion has pointed out, since other commentaries of Aquinas, as those on the De Interpretatione, the De Coelo, the De Generatione et Corruptione, the Meteorologica and the Politica remain unfinished, terminating either at the end of some book or at the end of some lesson.

The supposition that St. Thomas did not comment upon the last two books--XIII and XIV--because he lacked a Latin translation of them, cannot be maintained. Mansion noted the untenableness of such a hypothesis as early as 1925, using in support of his claim the earlier work of Pelster, mentioned above, which contains a collection of the various references to these books in certain works of St. Thomas and St. Albert the Great, which are evidently drawn from the media. But the most direct evidence of St. Thomas' knowledge of the last books is to be found in the many references made to them in the Commentary itself, especially in the early part of the work. The majority of such references are given in Book III, which contains the fifteen aporiae or difficulties that Aristotle intends to consider in the development of subsequent books. In lessons 4-15 of this book St. Thomas examines these difficulties, and in each lesson designates the respective books in which they will be treated. In so doing he refers to Books XIII and XIV and describes the problems with which they actually deal. In mentioning Book XIII he even cites the opening lines of chapter 1. The objection that such references have been added later in a second writing would have to be dismissed in the light of Pelster's later researches.

It therefore could not have been the lack of a translation that prevented St. Thomas from commenting upon the books in question; and inasmuch as he gives no explanation for bringing his work to a close at the point at which he did, we are forced to look elsewhere for an answer. Here the suggestion of Mansion appears to be the most reasonable one. He bases his opinion on a statement in Sylvester Maurus, who, in his synopsis immediately preceding Book XIII, says of the last two books that their teaching is most obscure and of little value, and that, in any event, since the subjects treated therein have already been dealt with in previous books, it would be pointless to dispute them any further. Sylvester is referring to the fact that in these books Aristotle gives a systematic criticism of the theory of Ideas as interpreted by Plato's successors, Speusippus and Xenocrates, who identified the Ideas with numbers and extensions; and since this subject has nothing to do with the development of Aristotle's metaphysical views, properly speaking, and has already been exposed in great detail in earlier books, St. Thomas probably thought it unnecessary to deal with it again.

The problems regarding Book XI are not as easily solved. It is generally admitted that this book was the last one to have been introduced into the West, and its translation would without doubt be due to William of Moerbeke. However, the time at which St. Thomas first came to know of the existence of this book, and then received and used the translation of it in his exposition, is still an open question. Two different and opposite stands have been taken in this matter--one by Mansion and the other by Pelster--and both have something to be said in their favor.

Mansion's position, later accepted by Salman, is that St. Thomas was unaware of the existence of Book XI at the beginning of his exposition and even after his work was well under way. He grounds his argument on the fact that St. Thomas makes no mention of this book at the start of his Commentary, and even fails to take account of it as late as Book VII; for in the schematic division given at the beginning of this book, in which the issues to be dealt with in the remaining books are outlined, no reference at all is made to Book XI. One large division covers Books VII to IX, and another covers Book X. But at the beginning of Book XI a new division is found, which, while not in absolute opposition to the previous one, is still not in complete agreement with it. Mansion concluded from this that, when St. Thomas composed his exposition of Book VII, he was either unaware of Book XI altogether, or at least had not yet received the translation of it, and so made no mention of it in his division. However, when this book came into his possession later on, he incorporated it into his work, and had therefore to make a new division which would account for it and also extend to the balance of his work. He would have received this new book just before he began his commentary of Book XII or after he had completed it; and assuming the later alternative to be true, it would then have been necessary for him to revise Book XII. Mansion feels that there is evidence to support such a second writing in a number of references given in early books, especially Book III, in which Book {L} is sometimes referred to as XI, following the numeration of the media.

In Pelster's view the hypothesis of Mansion deserves attention, but it is not necessary to accept it. That is to say, from the fact that St. Thomas in Book VII does not consider XI, it does not necessarily follow that he was unaware of it. He may have known it but simply found no occasion to use it. Since there is evidence that St. Thomas possessed the nova at the time he began his exposition, it is quite possible that he knew Book XI, which is found only in that version. He could have decided at first against using it and later changed his mind. This assumption is a reasonable one according to Pelster if certain facts are taken into consideration. St. Thomas in commenting upon Aristotle was interested primarily in explaining the development of his metaphysical views, and in this undertaking Book XI has no essential part to play, being neither a continuation of the thought of Book X nor an introduction in any necessary and proper sense to Book XII. This becomes evident when the contents of the book are examined, for they are merely a recapitulation of the main points developed in certain of the earlier books, to which extracts from the Physics have been added. This book then could easily have been set aside without in any way affecting the development of Aristotle's main trend of thought. Pelster feels that, when St. Thomas came to treat Book XI he decided to introduce it into his exposition as an introduction to Book XII inasmuch as it can be used as a kind of preparation for the doctrine presented in this book. St. Thomas' change of mind can be accounted for, he thinks, in the light of the circumstances under which the Commentary was written. St. Thomas composed his commentaries for the use of teachers and students in the schools, and since the vetus, the media and the translation from the Arabic were all considered to be first class texts and the ones customarily employed, he would also have used them. But since these versions lacked Book XI, he would not have had to take this book into account. The nova, being new, would not be well enough known at first to use as a classroom text. However, when it did become better known and its superiority was recognized, St. Thomas would have begun to employ it as his basic text, and so would have to consider Book XI which it contained.

Granted that this simpler hypothesis is acceptable, Pelster also thinks that it is unnecessary to admit a second writing or revision, in whole or in part, as others have proposed on the basis of the occasional appearances of the numeration of the media along with that of the nova. The designation of Book ({L}) sometimes as XI and sometimes as XII, and of Books ({M}) and ({N}) sometimes as XII and XIII, and sometimes as XIII and XIV, admits of a simpler explanation: since St. Thomas found himself in a transitional stage, he is sometimes thinking of the older numeration of the media, and sometimes of the newer numeration of the nova. His readers and custom would force him to use the older numeration, while his new findings would incline him to use the newer. If the degree of simplicity with which a hypothesis takes care of known facts determines its acceptableness, Pelster's hypothesis cannot be lightly dismissed.

The completing of this translation has been possible only as a result of the unfailing assistance I have received from several persons who have my most sincere thanks. I am quite unable to express my gratitude to Fathers Robert W. Schmidt and James J. Doyle, S.J., for their untiring patience in reading the greater part of the manuscript, for their criticisms and the innumerable valuable suggestions they have made in the matter of emendations. I am particularly indebted to Father Schmidt for his excellent supervision throughout the whole undertaking, and for locating a number of references, especially those to Avicenna. I also wish to acknowledge my indebtedness to Father Robert F. Harvanek, S.J., whose original interest in this work made its ultimate publication possible; and to Fathers George A. Curran, S.J. and Michael Montague, S.J. for their help in reading some parts of the manuscript.

J. P. R.