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Ptolemaeus Arabus et Latinus

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Work B.4

De cometis

A brief description of nine types of comets and their influence on earthly events. This chapter is one of the two additional chapters (with B.5) often found together with the Centiloquium in Plato of Tivoli’s translation (B.1.2) or in the ‘Mundanorum’ version (B.1.4), either at the beginning or at the end. It is related to v. 99-100 of the Centiloquium, which deal with comets, but its origin and exact relationship to the Centiloquium remain to be investigated. The text exists in three versions: (1) the standard version (‘Dixit Ptholomeus quod stelle cum caudis sunt 9…’), generally found together with the Centiloquium in Plato of Tivoli’s translation; (2) an expanded version of the former (‘Ptholomeus in hoc libro tricas et tricarum nomina posuit…’), generally found together with the Centiloquium in the ‘Mundanorum’ version; (3) a version attributed to Robert Grosseteste and consisting of the expanded version followed by Grosseteste’s last part of his own De cometis (ed. Panti, 326-328, lines 112-145). The latter version occurs in MSS Erfurt, UFB, Amplon. Q. 361; Florence, BM, C 163; and Munich, BSB, Clm 588. The text is attributed to Grosseteste in all three manuscripts and occurs among Grosseteste’s works in the Florence MS. Thomson saw no reasons to doubt the authenticity, but Panti, 249-251, argued against it, among others because the three extant copies are late and because the first part is not by him.


Standard version   ‘(ed. Boudet) Dixit Ptholomeus quod stelle cum caudis sunt 9, quarum prima est Veru, secunda Tenaculum, tercia Pertica — significabit mortalitatem multam et decollationem.’


Expanded version   ‘(ed. Boudet) Ptholomeus in hoc loco tricas et tricarum nomina posuit signa communium effectuum… Stelle cum caudis sunt 9 que mundum movent — quicquid ipsa significabit in regibus et divitibus apparebit.’


Version attributed to Grosseteste   ‘(Erfurt, UFB, Amplon. Q. 361) Incipit tractatus domini Ruberti Lynconiensis de cometis. Ptholomeus in hoc libro tricas et tricarum nomina ponit… Ptolomeus dixit quod stelle cum caudis sunt 9 — in regibus et divitibus apparebit. Et hec de cometis breviter discernimus. Trica est ignis sublimatus — qualitas rei future cuius est signum. Explicit tractatus domini Lynconiensis de cometis.’


F. J. Carmody, Arabic Astronomical and Astrological Sciences in Latin Translation. A Critical Bibliography, Berkeley-Los Angeles, 1956, 16-17 (no. 3d); R. Lemay, ‘Origin and Success of the Kitāb Thamara of Abū Ja’far Aḥmad ibn Yūsuf ibn Ibrāhīm from the Tenth to the Seventeenth Century in the World of Islam and the Latin West’, in Proceedings of the First International Symposium for the History of Arabic Science (Aleppo, April 5-12, 1976), Aleppo, 1978, II, 91-107: 102; R. Lemay, Abū Ma‘šar al-Balḫī [Albumasar]: Liber introductorii maioris ad scientiam judiciorum astrorum, Napoli, 1995-1996, IV, 143-144; R. Lemay, Le Kitāb at-Tamara (Liber fructus, Centiloquium) d’Abū Ja’far Aḥmad ibn Yūsuf [Ps.-Ptolémée], New York, 1999, I, 334-335 and passim; C. Panti, Moti, virtù e motori celesti nella cosmologia di Roberto Grossatesta. Studio ed edizione dei trattati De sphaera, De cometis, De motu supercelestium, Firenze, 2001, 153-156 and 245-252; J.-P. Boudet, ‘Les comètes dans le Centiloquium et le De cometis du pseudo-Ptolémée’, Micrologus 24 (2016), 195-226: 210-220. For the version attributed to Grosseteste, see also S. H. Thomson, ‘The Text of Grosseteste’s De cometis’, Isis 19 (1933), 19-25: 19; and S. H. Thomson, The Writings of Robert Grosseteste, Bishop of Lincoln (1235-1253), Cambridge, 1940, 112 (no. 65).


The standard version is edited by Lemay, Le Kitāb, I, 334-335 (from Berlin, SBPK, Hamilton 557) and Boudet, ‘Les comètes’, 211-212 n. 68 (from several MSS, with a French translation, 210-211); the expanded version by Boudet, ‘Les comètes’, 218-220 (from several MSS); and the version attributed to Grosseteste by L. Baur, Die philosophischen Werke des Robert Grosseteste, Bischofs von Lincoln, Münster, 1912, 36-39, together with his edition of Grosseteste’s De cometis (from Erfurt, UFB, Amplon. Q. 361 and Munich, BSB, Clm 588).