The volume contains critical editions of the extant parts of two hitherto unknown theological works by the
Būyid vizier al-Ṣāḥib b. ʿAbbād (d. 385/925), who is well known to have vigorously promoted the teaching of
Muʿtazilī theology throughout
Būyid territories and beyond. 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-Ṣāḥib’s education policy on the contemporaneous Jewish community in Cairo. The longer treatise of al-Ṣāḥib of ca. 350/960, possibly his
Kitāb Nahj al-sabīl fī uṣūl 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).