What was the name of the Greek physician, from 400 B.C., who showed that diseases have only natural, not supernatural, causes?

During the Classical period of ancient Greece, a monumental shift occurred in the understanding of human health. Prior to this era, sickness was widely viewed as a punishment from the gods or the result of supernatural forces. The Greek physician Hippocrates of Kos was the first to challenge these long-held beliefs, arguing that diseases were not caused by superstition but were instead the product of natural factors. He proposed that environmental factors, diet, and a person's lifestyle were at the root of illness, a revolutionary idea that separated the discipline of medicine from religion.

Often called the "Father of Medicine," Hippocrates was born on the island of Kos around 460 B.C. His approach laid the foundation for the scientific practice of medicine by emphasizing the importance of clinical observation. He and his followers meticulously recorded patient symptoms and case histories to better understand the course of different ailments. A famous example of his thinking is found in the treatise "On the Sacred Disease," which discusses epilepsy. At a time when the condition was believed to be a divine affliction, the author argued it was no more sacred than any other disease, having a natural cause originating in the brain.

This commitment to rational explanation established a new ethical and practical foundation for physicians. The extensive collection of medical texts associated with him, the Hippocratic Corpus, and the principles of the Hippocratic Oath have influenced the practice of medicine for centuries. His core principles, focusing on patient care, observation, and natural causes, marked the beginning of medicine as a rational science.