Dating of the Texts in which Aquinas Uses the Expression actus essendiJ. A. Weisheipl’s Datings

Entry 0374: Dating of the Texts in which Aquinas 
Uses the Expression actus essendi 

James A. Weisheipl’s Datings 

Commentary on the Sentences—Texts nos. 1, 2, 3, and 4:
About the commentary of the Sentences, Weisheipl 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).

Quaestiones disputatae De veritate—Texts nos. 5, 6, 7, and 8:
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).

Quodlibet 9—Text no. 9:

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).

Summa theologiae, part I—Text no. 10:
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).

Commentary on Boethius’s De hebdomadibus—Text no. 13:

Concerning the dating of Expositio libri Boetii De hebdomadibus, 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).