rhazes

Rhazes, also known as Abu Bakr Muhammad ibn Zakariya al-Razi, was a Persian polymath who lived circa 865–925 CE. He was born in Ray, near the modern city of Tehran, and his work spanned medicine, philosophy, chemistry, astronomy, and other disciplines. He is regarded as a major figure of the Islamic Golden Age and a forerunner of modern clinical science.

In medicine, Rhazes authored the Al-Hawi fi al-tibb (The Comprehensive Book on Medicine), a vast encyclopedia drawing on earlier authorities and his own clinical observations. The work was translated into Latin in the 12th century as the Continens and influenced medieval European medical practice. Rhazes wrote on a wide range of topics within medicine, including diet, pediatrics, psychiatry, ophthalmology, and the differentiation of diseases. He is credited with distinguishing smallpox from measles based on clinical features, an achievement noted for its emphasis on careful observation.

Beyond medicine, Rhazes contributed to early chemistry and experimental methods. He conducted experiments in distillation and the manipulation of substances, and he wrote treatises often referred to as the Book of Secrets, reflecting an interest in alchemy and practical laboratory knowledge. His skeptical, empirical approach toward inherited authorities, including Galen, helped promote observation and inquiry in medical practice.

Rhazes died in Ray around 925 CE. His writings influenced both Islamic and European medical traditions, and he remains cited as a foundational figure in the history of medicine and pharmacy.