The Ṣābi’ Family Library of Thābit ibn Qurra’s Works in Baghdad

Thābit ibn Qurra (d. 901 CE) was one of the notable scholars studying Greek science and philosophy in the early Abbasid period. He is especially known for his translations of important Greek scientific works. He established a family in Baghdad (the so-called “Ṣābiʾ family”), and the members of this family survived as court scholars, among whom was Abū Isḥāq Ibrāhīm ibn Hilāl al-Ṣābī (d. 994), a great-grandson of Thābit, who became the head secretary of the Buyid court. Most remarkable is the existence of an Arabic manuscript containing three works composed by Thābit, which Abū Isḥāq Ibrāhīm copied with recourse to an exemplar in Thābit’s handwriting: Istanbul, Köprülü MS 948. Moreover, Ibn al-Qiftī’s Taʾrīkh al-ḥukamāʾcited a list of Thābit’s works composed by Abū ʿAlī al-Muḥassin (d. 1010), a son of Abū Isḥāq Ibrāhīm. These facts suggest that this family, descended from Thābit, authorised his works by keeping his autograph exemplars and producing copies of his authentic works. In this article, by examining the contents of al-Muḥassin’s catalogue of Thābit’s works, the colophons of Köprülü MS 948 copied by Abū Isḥāq Ibrāhīm, and the correspondence concerning Apollonius’ mathematical works between Abū Isḥāq Ibrāhīm and al-Kūhī, I elucidate how the members of this family managed the works of its founder Thābit, protecting his reputation as an authority on Greek science and philosophy by controlling the copying of his works, and how they struggled to maintain their high position at the court by using Thābit’s legacy.