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Monday, October 27, 2014

0375: Dating of the Texts in which Aquinas
Uses the Expression "Actus Essendi" (X)



Entry 0375: Dating of the Texts in which Aquinas 

Uses the Expression "Actus Essendi(X)


1. Dating of the Commentary on the Sentences:

Aquinas uses the expression “actus essendi” in four passages in his Commentary on the Sentences:


1. In I Sententiarum, distinction 8, question 1, article 1, corpus.
2. In I Sententiarum, distinction 8, question 4, article 2, ad 2.
3. In I Sententiarum, distinction 8, question 5, article 2, corpus.
4. In III Sententiarum, distinction 11, question 1, article 2, ad 2.


The Commentary on the Sentences seems to have been written between 1252-1256, and the date of composition has been framed within the following setting:

After some difficulties with his blood family concerning his vocation to the Dominican Order, and “since his resolve remained unbroken, he [Aquinas] was permitted to rejoin the Dominican confreres and made his way to Paris in 1245. At Paris he first came into contact with Albert the Great during the period 1245-1248, and in 1248 he accompanied Albert to Cologne in order to continue his theological formation there. In 1252 he was sent back to Paris to begin working for the highest degree offered by the University there, that of Magister in Theology, and pursued the rigorous academic program required for this until 1256. Not least among his duties during this period was his responsibility to comment on the Sentences of Peter the Lombard, and this resulted in the eventual publication of his first major theological writing, his Commentary on the Sentences” (John F. Wippel, The Metaphysical Thought of Thomas Aquinas [Washington, D.C.: The Catholic University of America Press, 2000], xiii-xiv).

About the commentary on the Sentences, Weisheipl for his part writes that “According to William of Tocco, Thomas composed his Scriptum while he was Baccalaureus Sententiarum (1252-1256)” (James A. Weisheipl, Friar Thomas D’Aquino: His Life, Thought, and Works [Washington, D.C.: The Catholic University of America Press, 1983], 358).

These comments are in agreement with what Jean-Pierre Torrell wrote on this subject:

“Upon his arrival in Cologne, after Naples and Paris (and whatever may have been the details about his years of study), Thomas already had seven or eight years of formation behind him, even without counting what he learned on his own during the imprisonment by his family. Some scholars (De Groot, Berthier, Pelster) even think that he was already a lecturer in theology and probably the biblical bachelor for Albert (Scheeben, Eschmann). Weisheipl takes up this hypothesis and suggests that Thomas taught cursorie on Jeremiah, Lamentations, and a part of Isaiah at Cologne. … Weisheipl’s arguments are not without weight. On the one hand, he reminds us that Thomas was sent to Paris to lecture on the Sentences, not the Bible. Besides, he emphasizes that, if he had begun by reading the Bible, Thomas would have been an exception, since none of the masters who had occupied the second Dominican chair up until then had begun their teaching as bachelors with a cursory reading of the Bible. All had begun with the Sentences. Furthermore, by the middle of the thirteenth century it was no longer an absolute rule that the bachelor of the Sentences would earlier have been a biblical bachelor. Weisheipl’s suggestion is, therefore, well founded and it has been well received by accomplished scholars” (Jean-Pierre Torrell, Saint Thomas Aquinas: The Person and His Work - Volume 1, trans. Robert Royal [Washington. D.C.: The Catholic University of America Press, 2005], 27-28).

Torrell then adds:

 “The ampleness of this work [the Commentary on the Sentences] fits only with difficulty into the chronological framework that assigns the two first years in Paris to biblical teaching and the next two to the Sentences. But if we accept the solution that naturally suggests itself from the sources, we may spread out the composition of this immense, five-thousand-page commentary over a little more than four academic years (though the teaching, according to the university statutes, had to be completed within two years). All this accords with Tocco, who makes the time of composition spill over into the following period, not just the time of the ‘formed’ bachelor, but that of the master as well. [Footnote:] Ystoria 15, p. 236 (Tocco 14, p. 81): ‘Scripsit in baccellaria et principio sui magisterii super quatuor libros Sententiarum.’ We may thus understand Thomas’s achievement much better. He was far from thinking his work definitive, however, and, from all appearances, he modified it, trying to improve it, when he took it up again to deliver to his students at Santa Sabina almost a decade later” (Ibid., 45).

But Torrell makes clear that “it was not this return to the subject in Rome that came down to posterity, but the Paris lectura” (ibid., 47).


2. Dating of the Quaestiones disputatae de veritate:

Aquinas uses the expression “actus essendi” in four passages in his Quaestiones disputatae de veritate:

1. De veritate, question 1, article 1, corpus
2. De veritate, question 1, article 1, ad 1
3. De veritate, question 1, article 1, ad sc 3
4. De veritate, question 10, article 8, ad 13

There seems to be very little doubt that Aquinas wrote the Quaestiones disputatae de veritate in the period between 1256 and 1259.

Jean-Pierre Torrell states simply that “The disputed questions De veritate date from the three years of Thomas’s first period teaching as a master in Paris, from 1256 to 1259” (Jean-Pierre Torrell, Saint Thomas Aquinas: The Person and His Work - Volume 1, trans. Robert Royal [Washington. D.C.: The Catholic University of America Press, 2005], 334).

And in agreement with this John F. Wippel writes: “From 1256 until 1259 Thomas carried out the functions of a Master (Professor) of Theology at the University of Paris. These duties included conducting formal disputed questions (resulting in his Quaestiones disputatae De veritate) and quodlibetal disputations (where any appropriate question could be raised by any member in the audience, and would ultimately have to be answered by the presiding Master). His Quodlibets 7-11 and his Commentary on the De Trinitate of Boethius resulted from this period” (John F. Wippel, The Metaphysical Thought of Thomas Aquinas [Washington, D.C.: The Catholic University of America Press, 2000], xiv).

Torrell elaborates further on the issue of the date of composition of De veritate by offering the following remarks: “To return to De veritate … its existence is attested very early. Well before the deposition during the canonization process at Naples by Bartholomew of Capua (Processus canonizationis S. Thomae, Neapoli, ed. M.-H Laurent, in Fontes, 85, p. 388), a catalogue of Thomas’s works published prior to 1293 mentions the questions De veritate ‘quas disputavit Parisius.’ (This is the list of the ms. Praha, Metr. kap. A 17/2, of which we can find a transcription in M. Grabmann, Die Werke des hl. Thomas von Aquin: Eine literarhistorische Untersuchung und Einfuhrung, in Beitrage zur Geschichte der Philosophie und Theologie des Mittelalters 22 (1-2), pp. 97-98. …) But we have two other even earlier testimonies. Beginning in 1278, William de la Mare, Thomas’s Franciscan adversary, author of the famous Correctorium, dedicated a section of nine articles attacking the (in his eyes) faulty theses of the De veritate—an indisputable sign of Thomist authenticity. Thomas’s friends also evidently recognized this, since they came to his defense. (See some of the details of this subject in the Leon. ed., vol. 22/1, p. 6*. …) At a still earlier period, Vincent of Beauvais introduced (prior to 1264/65, the date of his death), in his second edition of the Speculum maius, important fragments from questions 11, 12, and 13 of the De veritate under the explicit name of their author. (See Leon., vol. 22, p. 7*, and p. 189* for a list of these borrowings by Vincent.) The use of the book was therefore practically contemporaneous with its completion, and this permits us to emphasize both the rapidity of its diffusion and the vitality of Parisian university circles at the time” (Torrell, Saint Thomas Aquinas: The Person and His Work, 63-64).

According to Weisheipl the questions De veritate “were disputed in Paris during Thomas’s first Parisian regency [1256-1259] and distributed over the course of three years. Thus questions 1-7 (in 67 articles) were disputed during the first year (1256-1257); questions 8-20 (in 99 articles) were disputed during the second year (1257-1258); and questions 21-29 (in 63 articles), during the third year (1258-1259)” (Weisheipl, Friar Thomas D’Aquino, 362-363).

Thus there seems to be very little doubt that Aquinas wrote the Quaestiones disputatae De veritate in the period between 1256 and 1259.

In his doctoral dissertation, The Philosophical Vocabulary of St. Thomas Aquinas in De Veritate, James E. Royce explores in greater detail the evidence that substantiate the assigned date of composition of De veritate.

Royce’s study relies on the work of Henry Denifle (1844-1905) who collected and edited documents referring to the history of the University of Paris during the time of Saint Thomas Aquinas. In his dissertation Royce writes a section entitled “De Veritate: Circumstances and Date of Its Composition.” Here I report the entire section.

Royce writes:

“Henry Denifle, O.P., the great authority on documentary sources for the history of the history of the University of Paris during the time of St. Thomas Aquinas, makes the remark in a note in the Chartularium Universitatis Parisiensis that the old lives of St. Thomas agree about one date if about nothing else: St. Thomas was made a magister in theology at the University of Paris in the year 1256” (Henrious Denifle et Aemilio Chatelain, Chartularium Universitatis Parisiensis, Delalain, Paris, 1889, I, 307, note 1).

“This is important, because it clinches beyond all doubt the dating of the Quaestiones Disputatae De Veritate. Biographers, historians, and critical scholars are in unanimous agreement that the work was the fruit of his first years of teaching at the University of Paris, immediately after he was advanced to the magisterium.

“The oldest sources for the life of St Thomas are in remarkable agreement on the facts of these years of St. Thomas’s life and work. A study of the writings of William of Tocco, Bernard Guido, and Peter Calo reveals that St. Thomas was made licentiate in theology in the early months of 1256, and master later in that same year. (See Friedrich Ueberweg, Grundriss der Geschichte der Philosophie [rev. Bernhard Geyer], Mittler and Son, Berlin 1928, II, 423. An excellent bibliography on the life of St. Thomas Aquinas is contained in P. Mandonnet and J. Destrez, Bibliographie Thomiste [Bibliotheque Thomiste, I], Le Saulchoir, Kain, Belgique, 1921, 1-7. More recent is the bibliography found in P. A. Waltz, O.P., ‘Chronotaxis Vitae et Operum s. Thomae de Aquino,’ Angelicum, 1939, XVI, 463-473. The Bollandists list the old sources and reproduce many of them, Acta Sanctorum: Martii, I, 655-657).

“Bartholomew, or Ptolemy, or Tolomey, of Lucca was a disciple of St. Thomas and a church historian who died in the year 1327. In his life of St. Thomas he says, ‘Post hoc, ipso magistrato, fecit Questiones de Veritate. Post tres annos magisterii sui redit in Italiam’ (Fide Pierre Mandonnet, O.P., Des Ecrits Authentiques de S. Thomas D’Aquin [2me edition], Saint-Paul, Fribourg, 1910, 59).

“Another early biographer, Bartholomew of Capua (Logotheta), a Sicilian who as a student followed the lectures of St. Thomas, dates the De Veritate as being written after St. Thomas was made master and during his first period of teaching· at Paris, before going to Italy in 1259 (Alexander Birkenmajer, ‘Kleinere Thomasfragen,’ Phi1osophisches Jahrbuch, 1921, XXXIV, 32).

“The English Dominican Nicholas Trevet, who died in 1328, made a catalogue of the works of St. Thomas between the years 1319 and 1323, in which he notes that St. Thomas ‘scripsit etiam primam partem de Quaestionibus disputatis de Veritate et ultra, quas Parisiis disputavit’ (Mandonnet, Des Ecrits Authentiques, 47-48).

“The older historians, following these sources, tell us that the young Thomas came to Paris in 1252 from the school of Albert the Great at Cologne, and spent the years 1252-1256 as a bachelor in theology in Paris. Although they agree that he was made master in 1256, there seems to be good evidence that the formal inceptio by which he was recognized as a master by the faculty of the University of Paris did not take place until October, 1257. This is the opinion of J. Echard in his life of St. Thomas. (See Echard-Quetif [Bibliothecae Scriptorum Ordinis Praedicatorum, Paris, 1719-. 1721, I, ad annum 1274], S. Thomae Aquinatis Opera, Simon Occhi, Venetiis, 1775, I, ix-xxv.) It is also the opinion of the church historian Fleury; of John Francis Bernard Maria de Rubeis (see Dissertationes Criticae etc. [Pasquali, Venetiis, 1750, Dissertatio XI, caput ii], S. Thomae Aquinatis Opera [ed. Leonina], Romae, 1882, I, clxxv); and of Ueberweg (see op. cit., 424). Since all agree that he left for Italy in 1259, Quaestio I of the De Veritate was almost certainly written in 1257. The editors of the Vives edition, however, say ‘1257 Parisiis… Laurea donatus, ab anno 1258 ad annum sequentem Questiones de Veritate … scripsit’ (Opera Omnia S. Thomae Aquinatis [ed. Stanislaus Edward Frette et Paul Mare], Apud Ludovicum Vives, Paris, 1871, I, xii).

“(The fact mentioned by the Bollandists in the Acta Sanctorum [Martii, I, ‘Commentarius praevius,’ 657b] that St. Thomas was made doctor of theology in the year 1253, must not be confused with his being made magister at the University of Paris, for the doctorate was always previous even to the licentiate in those days, and in this case was probably granted by the Dominican Order rather than by the University.)

“The most recent investigations confirm these conclusions. Dr. Martin. Grabmann in his Thomas von Aquin (F. Pustet, Munchen, 1926, 3-5) states that St. Thomas received his licentiate in 1256 and left Paris in 1259, and in his latest work on Die Werke des Hl. Thomas von Aquin (Aschendorff, Munster, 1931, 276, 280) he makes these the outside dates for the writing of the De Veritate. Pierre Mandonnet in the latest expression of his mind on the subject dates the De Veritate I as somewhere in the year 1256-1257. (See S. Thomae Aquinatis Quaestiones Disputatae, Lethielleux, Paris, 1925, ‘Introduction,’ I, 19. He here summarizes his ‘Chronologie des questions disputes de saint Thomas d’Aquin,’ Revue Thomiste, 1918, XXIII, 266-287, 341-371.) A most recent summary (1939) of the investigations on the subject lays down the following chronology:

1252-1256 Parisiis, Baccalaureus
1256 Obtenta licentia, fit magister in theologia
1257 a collegiis magister agnoscitur
1259 in Italiam rediit

and states that the disputed questions De Veritate date at the outside from 1256 to 1259. (See Walz, op. cit., 470.) From all this we gather that it is quite safe to assign the year 1257 as the extremely probable date for the first question, for it is certain that St. Thomas was at work on them by that time and it is highly probable that he at least did not progress very far during 1256.

“It must be noted that the controversies which raged for some time in the various European learned periodicals between Grabmann, J. Koch, Mandonnet, P. Synave, and others regarding the chronology of the disputed questions does not touch the date of the De Veritate at all, but centers rather around the dating of De Anima, De Spiritualibus Creaturis, and De Unione Verbi Incarnati. A good idea of these discussions can be obtained from the reviews in the Bulletin Thomiste for 1924 and 1926. (See Bulletin Thomiste, 1924, I, 58-61; III, 1-21 especially.) All the authorities, as well as all of the old catalogues, especially two ‘book lists’ of the University of Paris dating from 1275-1286 and 1292-1294 respectively, assure us that the De Veritate is the first of the disputed questions of St. Thomas. (See Denifle-Chatelain, Chart. Univ. Paris, I, 646.)

“The historical facts being established, it remains to interpret them in terms of their setting. The De Veritate represents the work of St. Thomas during a relatively early period in his productive career. But he was by this time no novice in the realm of philosophy and theology. He had been commenting on Peter the Lombard’s books of Sentences since 1252 and had committed the fruits of this teaching to writing. He had composed some seven or eight small philosophical works, including the De Ente et Essentia. He was by then a veteran of the battle which grew out of the antagonism which the secular clergy and laity of the University of Paris had shown toward the new Order of Preachers; as his own share in the controversy he had contributed the Contra Impugnantes Dei Cultum et Religionem. Now with William of St. Amour condemned and his own Order vindicated by the Pope, Aquinas began to teach as master of theology in one of the Dominican colleges which by that time had been incorporated into the University of Paris. (See J. Echard, Vita Santi Thomae, uses the expression, ‘Pacatis tandem rebus laurea donatus questiones de veritate disputavit …’ loc. cit., x.)

“This meant a very active engagement in the public scholastic life of that violently intellectual atmosphere. For in the Paris of that day school meant more than dull classroom routine. In the twelfth century a question arising out of the interpretation of scripture or some author, usually Peter the Lombard, had formed the basis of the lecture of the master. This easily turned into a discussion or dispute. The dispute finally detached itself from the lesson and became a separate exercise in its own right, being known as the ‘ordinary disputation.’ Every master in theology at Paris had to put on several of these ordinary disputations a year. According to Mandonnet and Synave St. Thomas held them as often as twice a week. Pelster and Birkenmajer disagree with the methods used to arrive at that conclusion, but only, it would seem, in order to dispute about the chronology of some of the later Quaestiones Disputatae. At any rate, he certainly held them oftener than a few times a year (see F. Pelster, review of P. Synave, ‘Le Probleme chronologique des questions disputees de S. Thomas d’Aquin,’ Scholastik, 1926, I, 587-590; and of Birkenmajer, see op. cit., 36-45).

“The subject was fixed in advance, and was usually confined to a single topic although more than one might be discussed if they were related. All the classes of the other bachelors and masters ceased for that morning, and we may imagine with what curiosity they flocked to the disputation hall of the brilliant young disciple of the Aristotelian Albert, already making a name for himself. At this session, however, the magister only presided; he might summarize and otherwise help, but the bachelors did the arguing. The next day, or the first day on which nothing prevented, there followed the magisterial ‘determination,’ the formal recapitulation and pronouncement of the master upon the subject of the previous disputation. Bachelors could not ‘determine,’ this being the sole right of the master, though the preliminary arguments which he presented were usually those proposed by the bachelors the day before. The Quaestiones Disputatae as we have them are the written form, then, not of the disputation but of the determinatio of the master. (See Hastings Rashdall, The Universities of Europe in the Middle Ages [new ed. Rev. F. M. Powicke], Clarendon Press, Oxford, 1936, I, 490-496; Mandonnet, Quaestiones Disputatae, ‘Introduction,’ I, 8-15.) Each article of the present form represents one such determination. We possess 510 of these written by St. Thomas, of which 253 are under the general title De Veritate, though only twelve are included under the first question which really forms the treatise bearing that name.

“These disputations with their magisterial determinations gave St. Thomas a chance to work out at great length and in a controversial atmosphere much of what he was later to set forth more positively and succinctly in the two Summas. They do not, it is true, represent his best period, namely that from 1268 (when he got hold of certain material in translation from the Greek) until his death in 1274. Yet they do form an important part of his writings being often his fullest treatment of a topic. The De Veritate shows a decisiveness and a firmness of touch not observed in the commentaries on the Sentences. The problems essayed are difficult, the manner of their treatment profound and skillful. Since in them historical background is more prominent than in the Summa Theologica, they reflect better the doctrinal milieu in which he was working.”

See James E. Royce, “The De Veritate: Circumstances and Date of Its Composition,” chapter I in The Philosophical Vocabulary of St. Thomas Aquinas in De Veritate I, Doctoral Dissertation, Loyola University, Chicago, Illinois, 1945, 1-7.


3. Dating of the Summa theologiae, part I:

Aquinas uses the expression “actus essendi” in the Summa theologiae only once in part I, question 3, article 4, ad 2.

Concerning the dating of the Prima Pars, there seems to be very little doubt that Aquinas wrote it in Rome in the period between 1266 and 1268.

Wippel writes that “Thomas returned to Italy in 1259 and served there at various Dominican houses of study as Lecturer or as Regent Master, continuing to teach and to write at a rapid pace. During this period he completed his Commentary on the De anima, thereby commencing a series of intensive studies of Aristotle which would eventually result in partial or total commentaries on twelve works by the Stagirite. He completed his Summa contra Gentiles (1259-1265) and the Prima Pars of the Summa theologiae (1266-1268). Also dating from this period are his Exposition on the Divine Names (of Pseudo-Dionysius), Disputed Questions on the Power of God (De potentia), Disputed Questions on Spiritual Creatures, Disputed Questions on the Soul, and many other works of a theological or religious nature” (John F. Wippel, The Metaphysical Thought of Thomas Aquinas [Washington, D.C.: The Catholic University of America Press, 2000], xiv).

In 1259 Aquinas took part in the General Chapter of the Dominicans in Valenciennes, France, where he was a member of a commission that established the Dominican Order’s program of studies.

Soon after that, Aquinas returned to Italy. From 1261 to 1265, he was in Orvieto, where Pope Urban IV, who had high esteem for Aquinas, commissioned him to compose the liturgical texts for the Feast of Corpus Christi, the feast which, in addition to Holy Thursday, commemorates the institution of the Eucharist.

From 1265 until 1268 Thomas Aquinas lived in Rome where he directed the Study House of the Dominican Order. And in 1269 he was recalled to Paris for a second cycle of lectures.

Franklin T. Harkins reports more precisely that “From his inception at Paris in the Spring of 1256 until he stopped writing in Naples on 6 December 1273, Thomas Aquinas was—above all else—a teacher of sacred doctrine, a master of theology. (See Josef Pieper, Guide to Thomas Aquinas, trans. Richard and Clara Winston [Notre Dame, IN: University of Notre Dame Press, 1987], 89-102.)

“On 8 September 1265, not quite a decade into his teaching career, Thomas was charged by his Dominican provincial chapter at Anagni ‘for the remission of his sins’ with establishing and directing a studium at Rome for the education of select friars. (See Leonard E. Boyle, The Setting of the Summa theologiae of Saint Thomas [Toronto: Pontifical Institute of Mediaeval Studies, 1982], 8-15; Jean-Pierre Torrell, Saint Thomas Aquinas, vol. 1: The Person and His Work, rev. ed., trans. Robert Royal [Washington, D.C.: The Catholic University of America Press, 2005], 142-59; and M. Michèle Mulchahey, ‘First the Bow is Bent in Study….’ Dominican Education before 1350 [Toronto: Pontifical Institute of Mediaeval Studies, 1998), 278-306.])

“Having served the previous four years as conventual lector at Orvieto where he was responsible for the pastoral formation of the fratres communes, Aquinas had by this time become quite well aware of the deficiencies then characterizing Dominican education, particularly its narrow emphasis on applied and moral theology. (See Mulchahey, ‘First the Bow is Bent in Study….’, 184-203; Boyle, The Setting of the Summa theologiae, 1-8; and Torrell, Saint Thomas Aquinas 1, 117-20.)

“As head of his studium at Santa Sabina in Rome Master Thomas took terrific advantage of the opportunity to devise a new, more comprehensive theological curriculum for his young Dominican students by beginning to compose—and presumably teach—the Summa theologiae. (See Boyle, The Setting of the Summa theologiae.)”

This passage is from Franklin T. Harkins, “Primus doctor Iudaeorum: Moses as Theological Master in the Summa Theologiae of Thomas Aquinas,” The Thomist 75 (2011): 91-92.

Regarding the Prima Pars of the Summa theologiae, Weisheipl writes that Aquinas “did not begin work on the Summa until 1266, when he discarded his plan to rework his commentary on the Sentences. The prima pars was completed in 1268, before Thomas was sent to Paris for a second time. Part I, q. 79, a. 4, was completed after November 22, 1267, for he utilized Themistius’s paraphrase of Aristotle’s De anima, translated at this date by William of Moerbeke. Therefore the whole prima pars seems to have been written between 1266 and the spring of 1268” (Weisheipl, Friar Thomas D’Aquino, 361 as corrected on p. 479).

And Torrell points out that “It seems certain that during the time he was at Rome [from 1265] until September 1268, Thomas composed the Prima Pars in its entirety and that this portion [of the Summa theologiae] was in circulation in Italy even before his return to Paris [in 1269]” (Jean-Pierre Torrell, Saint Thomas Aquinas: The Person and His Work - Volume 1, trans. Robert Royal [Washington. D.C.: The Catholic University of America Press, 2005], 146).


4. Dating of the Quaestiones disputatae de potentia:

Aquinas uses the expression “actus essendi” in the Disputed Questions on the Power of God (De potentia) only once, in question 7, article 2, ad 1.

Scholars seem to have fixed the date of composition of De potentia. After returning to Italy in 1259, Aquinas first worked in Orvieto from 1261 to 1265, and then he moved to Rome where he directed the Study House of the Dominican Order from 1265 to 1268. There seems to be very little doubt that it was during this period in Rome that Aquinas wrote the disputed questions De potentia.

Referring to this teaching activity of Aquinas in Rome, Torrell accordingly remarks that “the disputed questions De potentia are precisely situated in this period” (Jean-Pierre Torrell, Saint Thomas Aquinas: The Person and His Work - Volume 1, trans. Robert Royal [Washington. D.C.: The Catholic University of America Press, 2005], 161).

Weisheipl for his part comments that “De potentia is chronologically and speculatively the immediate predecessor of the first part of the theological Summa” (James A. Weisheipl, Friar Thomas D’Aquino: His Life, Thought, and Works, 2nd ed. [Washington. D.C.: The Catholic University of America Press, 1983], 200). Aquinas wrote the Prima Pars of the Summa theologiae in Rome in the period between 1266 and 1268.

And concurring with this, Susan C. Selner-Wright begins the introduction of her translation of De potentia, question 3, by saying that “Thomas Aquinas wrote his Disputed Questions On the Power of God (Quaestiones disputatae de potentia Dei or De potentia) in Rome in 1265–66. It was begun, but probably not completed, before he began the first part of his most famous work, the Summa theologiae, also composed during this time in Rome” (Thomas Aquinas, On Creation: Quaestiones Disputatae de Potentia Dei-Q. 3, trans. S. C. Selner-Wright, [Washington. D.C.: The Catholic University of America Press, 2011], vii).


5. Dating of the Quodlibet 9:

Aquinas uses the expression “actus essendi” in the quodlibetal questions only once, in Quodlibet 9, question 4, article 1, corpus.

There seems to be very little doubt that Quodlibet 9 was written between 1256 and 1259 when Aquinas was regent master in theology at the University of Paris.

Wippel, for example, writes that “From 1256 until 1259 Thomas carried out the functions of a Master (Professor) of Theology at the University of Paris. These duties included conducting formal disputed questions (resulting in his Quaestiones disputatae De veritate) and quodlibetal disputations (where any appropriate question could be raised by any member in the audience, and would ultimately have to be answered by the presiding Master). His Quodlibets 7-11 and his Commentary on the De Trinitate of Boethius resulted from this period” (John F. Wippel, The Metaphysical Thought of Thomas Aquinas [Washington, D.C.: The Catholic University of America Press, 2000], xiv).

About the dating of Quodlibet 9, Weisheipl writes that the quodlibetal questions “fall into two groups, the earliest of which is the grouping 7-11 in a never varying series, and 1-6, which often vary in the manuscripts. … The group 7-11 belongs to Thomas’s first Parisian regency, [1256-1259]” (Weisheipl, Friar Thomas D’Aquino, 367).

And towards the end of his book, Torrell writes that “Thomas’s Quodlibets can be divided into two groups, according to the two periods of teaching in Paris. Quodlibets I-VI and XII (the reportatio of the latter was not revised by Thomas) come from the second period (1268-72)” (Jean-Pierre Torrell, Saint Thomas Aquinas: The Person and His Work - Volume 1, trans. Robert Royal [Washington. D.C.: The Catholic University of America Press, 2005], 337). In other words, by process of elimination, Quodlibet 9 belongs to the group written during the first Paris regency.

Earlier Torrell was more specific about the dating of the quodlibetal questions: “As to dates, after the first tentative steps, the researchers have reached agreement on dividing the Quodlibets into two groups according to the two Parisian sojourns: Quodlibets VII-XI belong to the first period [1256-1259], while Quodlibets I-VI and XII (the reportatio of this latter was not revised by Thomas) belong to the second [1268-72]” (Torrell, Saint Thomas Aquinas, 208-209).

Torrell explains that at the time of Aquinas at the University of Paris there were two types of disputed questions, private and public. “The first, private dispute (disputatio privata), was held within the school—the master with his students and bachelor only. The second type was public (disputatio publica or ordinaria), and the master had to hold it at regular intervals, though many willingly dispensed themselves from it, for the exercise could be perilous.”

“The difference between the first and the second form was therefore the public,” Torrell adds, “since the students from other schools could attend, and sometimes masters as well. On occasion, they did not refrain from raising difficulties for the colleague engaged in the exercise. In one of its forms,” Torrell continues, “this second genre of disputed questions could even be a solemn public occasion (the famous Quodlibets), which were held twice a year, during Lent and Advent. They interrupted the regular courses at the university. As a result of P. Mandonnet’s labors, we can agree today in dating from this first period of teaching in Paris [1256-1259] Thomas’s Quodlibets VII though XI” (Torrell, Saint Thomas Aquinas, 60-61).


6. Dating of the Commentary on Aristotle’s Metaphysics:

Aquinas uses the expression “actus essendi” only once in his Commentary on Aristotle’s Metaphysics, in the commentary on book 4, lecture 2, paragraph no. 6.

Aquinas’s Commentary on the Metaphysics seems to have been written between 1270 and 1272. Here are some remarks concerning the date of composition of this work.

Commenting on the derivation of the predicaments reported in the Commentary on Aristotle’s Physics and in the Commentary on Aristotle’s Metaphysics, John F. Wippel notes that “While there is no substantial disagreement between these two attempts on Thomas’s part to derive the ten predicaments, we may wonder which comes later in time. It is as difficult to answer this question with certainty as it is to determine whether the Commentary on the Metaphysics is prior to the Commentary on the Physics, or perhaps vice versa. In fact, Weisheipl suggested that Thomas may have been working on the two commentaries at approximately the same time -- the Physics (at Paris from 1270 to 1271) and the Metaphysics (at Paris, and possibly at Naples, from 1269 to 1272). As Weisheipl also warns, we should not assume that Thomas composed his Commentary on the Metaphysics, at least in its final version, in the order in which we number its books today. While accepting this final point, Torrell places the Commentary on the Physics during the earlier part of Thomas’s second teaching period at Paris, ca. 1268-1269. Although he acknowledges the uncertainties surrounding the dating of the Commentary on the Metaphysics, he suggests that its beginning may date from the academic year 1270-1271, with the Commentary on Books VII-XII falling after mid-1271 but before 1272-1273. Since Torrell has been able to take into account more recent research concerning this, he should be followed on this point. Consequently, it now appears that Thomas’s derivation of the predicaments in his Commentary on the Metaphysics expresses his most mature thought on this issue” (John F. Wippel, The Metaphysical Thought of Thomas Aquinas [Washington, D.C.: The Catholic University of America Press, 2000], 223-224).

Torrell points out that by the end of 1271, Thomas had adopted the numbering of the books of the Metaphysics of William of Moerbeke’s translation. “This fact,” Torrell explains, “is too little known by the average reader of Saint Thomas, but its importance is great. Until Moerbeke’s translation, one referred to the Metaphysics according to the translation by Michael Scot or according to the Translatio media, which was anonymous; both having omitted book Kappa, the book designated Lambda was referred to as book XI. William of Moerbeke is the first to translate book Kappa, which in his translation will become XI, while the book Lambda will become book XII. This criterion has permitted us to divide Saint Thomas’s works into two series, the one which dates before the Moerbecana, where the book Lambda is called XI, the other which dates from after the Moerbecana, when book Lambda is called XII. … The key date, which is to say the date when Saint Thomas knew the Moerbecana of the Metaphysics, is situated towards the middle or the end of 1271” (Jean-Pierre Torrell, Saint Thomas Aquinas: The Person and His Work - Volume 1, trans. Robert Royal [Washington, D.C.: The Catholic University of America Press, 2005], 225, n. 2).

Torrell, however, affirms that “The date and place of composition for the commentary on Aristotle’s Metaphysics pose numerous problems. The designation of Book Lambda as Book XII, a title that Thomas adopted toward the middle of 1271, invites us to date the commentary on Books VII-XII after that date. The beginning of the commentary may date from the academic year 1270-71. The commentary on Books II and III may be the fruit of self-correction or of later editing. Begun in Paris, the composition of this work may have been finished in Naples. The only sure thing, in the current state of research, is that this text is earlier than the De caelo et mundo, probably composed in Naples, 1272-73” (Torrell, Saint Thomas Aquinas, 344).


7. Dating of the Commentary on Boethius’s De ebdomadibus:

The expression “actus essendi” appears twice in Aquinas’s commentary on Boethius’s De Hebdomadibus.

This work seems to have been composed between 1257 and 1259, during Aquinas’s first regency in Paris. This is the opinion of Eleonore Stump who writes: “Aquinas’s commentaries on Boethius’s De Trinitate (On the Trinity) and De Hebdomadibus (sometimes referred to as ‘How Substances are Good’) are his other philosophically important writings from this period of his first regency” (Aquinas [New York: Routledge, 2003], p. 4).

The Oxford Handbook of Aquinas also situates the composition of the commentary on Boethius’s De Hebdomadibus around 1257-1259, the same date that they report for the composition of the commentary on Boethius’s De Trinitate. (See The Oxford Handbook of Aquinas, ed. Brian Davies and Eleonore Stump [New York: Oxford University Press, 2012] 534.)

Brendan Thomas Sammon places the composition of this commentary on 1258. (See B. T. Sammon, The God Who Is Beauty [Eugene, Oregon: Pickwick Publications, 2013] 207.)

Concerning the dating of Expositio libri Boetii De ebdomadibus, Weisheipl affirms that this commentary is generally dated in conjunction with the Super Boetium De trinitate “as being written during the first Parisian regency, 1256-1259” (Weisheipl, Friar Thomas D’Aquino, 382). Earlier in the book Weisheipl had remarked that in the catalogues, the In librum Boethii De hebdomadibus “is listed with In Boethium De trinitate, and many scholars accept the association, dating both around 1256-1259” (ibid., 138).

Torrell, for his part, seems to agree with this dating but is inclined to think that the commentary on Boethius’s De Trinitate was written first. Thus Torrell writes: “Historians habitually mention these two works one after another because of their common subject. In the preface to the Leonine edition, Father Bataillon thinks instead—given the internal data that reveal differences—that the Expositio libri Boetii De ebdomadibus is probably later than the Super Boetium De Trinitate. But without external data that would permit us to situate it better (through dated sources, for example), Bataillon declares himself unable to propose a precise date” (Jean-Pierre Torrell, Saint Thomas Aquinas: The Person and His Work - Volume 1, trans. Robert Royal [Washington, D.C.: The Catholic University of America Press, 2005], 68). Torrell then concludes that “The date of this work is doubtless later than that of the other commentary on Boethius, but the current state of research does not allow us to specify the date further, nor its circumstances” (Torrell, Saint Thomas Aquinas, 345-346).