Sabine Schmidtke, Professor in the School of Historical Studies, has authored Al-Sāhib Ibn ʿAbbād Promoter of Rational Theology (Brill, 2016), which contains critical editions of the extant parts of two hitherto unknown theological works by the Būyid vizier al-Sāhib b. ʿAbbād (d. 385/925). The manuscripts on which the edition is based come from Cairo Geniza store rooms. They consist of two manuscripts for each of the two texts—testimony to the impact of al-Sāhib’s education policy on the contemporaneous Jewish community in Cairo. The longer treatise of al-Sāhib of ca. 350/960, possibly his Kitāb Nahj al-sabīl fī usūl al-dīn, appears to be the earliest Muʿtazilī work preserved among the Jewish community. The second, briefer treatise also contains a commentary by ʿAbd al-Jabbār al-Hamadānī (d. 415/1025).