Abū Ḥayyān al-Tawḥīdī, ʿAlī b. Muḥammad b. al-ʿAbbās (ca. 310–414/922–1023), was a man of letters and a philosopher. According to evidence in his own writings it is estimated that he was born during the second decade of the 4th century of the hijra, probably in 310/922 (Yāqūt, 15/20; Ibrāhīm, 16–17; Muḥyī al-Dīn, 10; Qazwīnī, 2/167), either in Shīrāz, Nīsābūr or Wāsīṭ (see Yāqūt, 15/5; al-Ṣafadī, 22/39; al-Subkī, 4/2).

According to Yāqūt (15/5), who wrote the most extensive account of Abū Ḥay…