Abū Saʿīd al-Yamāmī, al-Faḍl b. ʿĪsā (d. between 421–430/1030–1039), was a physician and astronomer. Our knowledge of his life and circumstances is extremely limited. All that is known is that he lived in Baṣra, studied under Abū al-Faraj b. Ṭayyib (q.v.) and achieved high rank in the government of the Būyids (al-Qifṭī, 407; Ibn Abī Uṣaybiʿa, 1/240). From the fact that a work by Ibn Sīnā (Avicenna), Maqāla fī al-quwā al-ṭabīʿiyya, is addressed to him, it can be inferred that he was a well-known figure among his contemporaries, and had correspondence or acquaintanc…