Greek culture, renowned for its masterpieces of art, poetry, drama, and philosophy, also made great advances in medicine. The earliest Greek medicine still depended on magic and spells. Homer considered Apollo the god of healing. Homer's Iliad, however, reveals a considerable knowledge of the treatment of wounds and other injuries by surgery, already recognized as a specialty distinct from internal medicine.

By the 6th century bc, Greek medicine had left the magic and religious realm, instead stressing clinical observation and experience. In the Greek colony of Crotona the biologist Alcmaeon (lived about 6th century bc) identified the brain as the physiological seat of the senses. The Greek philosopher Empedocles elaborated the concept that disease is primarily an expression of a disturbance in the perfect harmony of the four elements-fire, air, water, and earth-and formulated a rudimentary theory of evolution.

Kos and Cnidus are the most famous of the Greek medical schools that flourished in the 5th century bc. Students of both schools probably contributed to the Corpus Hippocraticum (Hippocratic Collection), an anthology of the writings of several authors, although popularly attributed to Hippocrates, who is known as the father of medicine. Hippocrates was the greatest physician in antiquity. He convinced physicians that disease had identifiable causes and was not due to the supernatural. His writings were used in medical textbooks well into the 19th century. Greek physicians introduced such modern ideas as prognosis, or outcome of disease, and the use of case histories of actual patients to teach students. The highest ethical standards were imposed on physicians, who took the celebrated oath usually attributed to Hippocrates and still used in modified form today.

Although not a practicing physician, the Greek philosopher Aristotle contributed greatly to the development of medicine by his dissections of numerous animals. He is known as the founder of comparative anatomy. Further progress in understanding anatomy flourished by the 3rd century bc in Alexandria, Egypt, which was firmly established as the center of Greek medical science. In Alexandria the anatomist Herophilus performed the first recorded public dissection, and the physiologist Erasistratus did important work on the anatomy of the brain, nerves, veins, and arteries. The followers of these men divided into many contending sects. The most notable were the empiricists who based their doctrine on experience gained by trial and error. The empiricists excelled in surgery and pharmacology; a royal student of empiricism, Mithridates VI Eupator, king of Pontus, developed the concept of inducing tolerance of poisons by the administration of gradually increased dosages.