Al-Razi (Rhazes)

Al-Razi, known in Latin as Rhazes, was a Persian physician, hospital director, and philosophical author. His clinical writings compared symptoms and case histories and attempted to distinguish diseases that could look similar. A famous treatise differentiated smallpox from measles more clearly than many earlier accounts, although its explanations and treatments belong to premodern medicine.

Al-Razi valued observation and criticized authorities when experience did not match inherited claims. Works associated with him discuss pharmacy, diet, ethics, and the organization of care. Stories about his hospital practice are sometimes repeated without strong contemporary evidence, so his reputation should rest on the substantial texts that survive. Those writings show medicine developing through compilation, comparison, bedside experience, and debate across Greek, Persian, Indian, and Arabic traditions.