known in the Latin West as Rhazes (b. Rayy, south of today’s Teheran, Iran, 1 Sa'ban 251/28 August 865; d. Rayy, 5 Sa'ban 313/26 October 925 [or perhaps ten years later, 935?]), medicine, alchemy, logic and philosophy, religious criticism. For the original article on Al-Rāzī see DSB, vol. 11.

Since Shlomo Pines wrote his entry for the original Dictionary of Scientific Biography (1975), only a few new data have emerged about Rāzī’s life. The situation that the rich bio-bibliographical share of classical and medieval Arabic literature conspicuously neglects Rāzī has not changed, and the well-known reasons for this—Rāzī’s distance from the caliph’s capital Baghdad for the greater part of his life, and more saliently, his position as an outsider to the scholarly establishment and as a freethinker— remain the same. However, the precise dates of his birth and death recorded by al-Bīrūnī in his account of Rāzī’s works may well be trusted. The information that the debate between Abū Bakr al-Rāzī and Abū Hatim al-Rāzī was conducted before the governor of Rayy, Mardāwīj, who took over the town only in 930 CE, would suggest a later year of death for Rāzī (as later authorities have it), but it has been plausibly argued that the actual governor was not Mardāwīj, but Ahmad b. 'Ali who died in 923 or 924 CE. Bīrūnī’s precise recording of Rāzī’s dates might also serve to credit his family with a certain level of education and affluence, which would also have facilitated his access to the scholarship to which his works amply attest. Rāzī’s scholarly relations include two students of the philosopher al-Kindī, al-Sarakhsi and Abū Zayd al-Balkhi, the latter of whom he mentions as his teacher in philosophy and for whom he in turn wrote a recipe—an early example of its kind—against Abū Zayd’s rose allergy during spring in Balkh. He exchanged letters on religious-philosophical problems with some other colleagues from Balkh, Abū l-Qāsim al-Ka'bi and Abū l-Husayn Shahid. Rāzī’s only known disciple is the Christian philosopher Yahyā ibn 'Adī, who later went on to study with the famous philosopher al-Farābī (d. 950).

Medical Writings Rāzī’s largest medical work, and the work for which he was most famous in the Latin tradition, K. al-Hāwī (Continens), still represents a largely unexploited treasure of medical information, much of it otherwise lost, from Greek, Sanskrit, Syriac, and early Islamic sources, complemented by his own clinical observations (introduced by li, meaning as for myself) on diagnosis and therapy. The complicated manuscript history of the text has not been investigated since 1975 (and will probably remain a desideratum for some time), but a few studies show that the Hāwī is composed of a series of thematically neighboring, yet independent, monographs. These studies illustrate the method of composition and prove that the choice of quotations (entirely from written sources) and their authenticity have to be examined from instance to instance, and that the ultimate product is not Rāzī's. Rather, it was written after...