The Persian physician al-Razi (ca. 865-925), also known as Rhazes, prepared compilations that were influential in Western medicine for centuries. His monograph on smallpox and measles is still considered a medical classic.

Abu Bakr Muhammad ibn Zakariya al-Razi was born at Ray, a city not far from modern Teheran in northeastern Iran. He is believed to have devoted his early years to the study of music and philosophy. An accomplished lute player and singer, he enjoyed music throughout his life and even compiled an encyclopedia on the subject. According to one Islamic biographer, however, he never truly grasped the purpose of metaphysics and finally abandoned philosophy for more practical pursuits. He may even have earned his living for a time as a banker or money changer.

Authorities differ on precisely when al-Razi began to study medicine. Some maintain that he first left Ray and journeyed to Baghdad as...