Translated from the Greek by William of Moerbeke before 1272 and probably between 1266 and 1269. As shown by Vuillemin-Diem/Steel, the Greek model (now lost) used by William often offers superior readings to those of all (47) the surviving Greek manuscripts, so that the resulting Latin text allows us to improve on the critical edition of the Greek original. William’s translation remained little known, but it was used by Thomas Aquinas, Henry Bate of Mechelen and probably Agostino Nifo (see C.2.15).

Text ‘(ed. Vuillemin-Diem/Steel) [book i] In primo libro iudicialium Claudii Ptholomei ad Syrum insunt ista capitula… (chapter index). Prohemium. Capitulum primum. Hiis qui instituunt per astronomiam pronosticum finem, o Syre, cum duo insint maxima et principalissima: unum quidem quod primum est ordine et virtute — se habentes impotentes penitus existent. Finis libri primi. [book ii] Hec sunt capitula libri secundi… (chapter index). Divisio totius intentionis. Capitulum primum. Principaliora quidem preexpositorum nobis tabulariter ad considerationem particularium prenuntiationum — in consequentibus secundum convenientem consequentiam aggrediemur. Explicit liber secundus. [book iii] Hec sunt capitula libri tertii… (chapter index). Prohemium. Capitulum primum. Pertracta nobis in precedentibus theoria que est circa universalia simptomata — quod passionum facile mobilius et multiformius et quod facile profectibilius. Explicit liber tertius. [book iv] Incipit liber quartus. Prohemium. De fortuna possessoria… (chapter index). Prohemium. Capitulum primum. Que quidem igitur ante nativitatem — Consummata iam geneatici sermonis specie summatim, bene utique habebit huic tractatui convenientem imponere finem. Explicit liber quartus Ptholomei.’

Bibl. A. A. Björnbo, ‘Die mittelalterlichen lateinischen Übersetzungen aus dem Griechischen auf dem Gebiete der mathematischen Wissenschaften’, in Festschrift Moritz Cantor anläßlich seines achtzigsten Geburtstages gewidnet von Freuden und Verehrern, Leipzig, 1909, 93-102: 99 (no. 17); C. H. Haskins, Studies in the History of Mediaeval Science, Cambridge, 1927 (2^nd ed.), 111-112; F. J. Carmody, Arabic Astronomical and Astrological Sciences in Latin Translation. A Critical Bibliography, Berkeley-Los Angeles, 1956, 19 (no. 10e); L. Anthonis, ‘Iudicialia ad Syrum: Une traduction de Guillaume de Moerbeke du Quadripartitum de Cl. Ptolémée’, in Guillaume de Moerbeke. Recueil d’études à l’occasion du 700^e anniversaire de sa mort (1286), eds J. Brams, W. Vanhamel, Leuven, 1989, 253-255; G. Vuillemin-Diem, C. Steel, Ptolemy’s Tetrabiblos in the Translation of William of Moerbeke. Claudii Ptolemaei liber iudicialium, Leuven, 2015.

Modern ed. Vuillemin-Diem/Steel.