The scientific work of Jews in the Islamic world represents an important part of the history of science in Jewish civilization. To begin with, there are reports, though difficult to verify, that a Jewish physician in Syria, Māsarjawayh, translated a Syriac text on medicine into Arabic in 684. Then, the best-known astrologer of the Abbasid Caliphate, Māshāʾallāh (d. ca. 810–815), was Jewish, and was among those responsible for ascertaining the most propitious time for the founding of Baghdad. Of Māshāʾallāh’s writings in Arabic, only excerpts and cita…