Hippocrates, Galen, and The Greek Physicians

Hippocrates (460–377 b.c.e.) has been called the father of Greek medicine. The young Hippocrates observed his physician father and his peers practicing the healing art.

He traveled throughout Greece and possibly as far as Libya and Egypt. Ptolemy Soter (323–285 b.c.e.), an Egyptian pharaoh, published a collection of treatises by Hippocrates and his followers for the library at Alexandria.

Hippocrates is best known for his dictum that if the physician could not take away suffering then he must at least alleviate it. He used observation to document physical symptoms and behavior, in contrast to making offerings and appealing to supernatural forces.

He took into account the interplay of three variables: the patient, the physician, and the disease. He stressed the importance of hygiene and believed that the doctor belonged at the side of the patient rather than in a temple far away.


Although he did not use the term immune system, he recognized that there were individual differences that affected the severity of any affliction. Of the Epidemics offers one of his best writings, describing a mumps epidemic. The Corpus Hippocraticum gives an excellent overview of Greek medicine in the fifth century b.c.e.

The Hippocratic oath is a traditional part of a contemporary physician’s rite of passage from student to doctor. The oath begins with a pledge to Apollo, Asclepius his son, and his daughters, Hygeia and Panacea.

It stresses the mentoring relationships and the lifelong relationship of the physician to the person who taught him the healing arts. There is a promise not to help a patient commit suicide. There is also a statement about privacy and confidentiality.

Not all Greek physicians practiced by Hippocratic dictates, but all accepted the humoral theory as the basis for human physiology. In this theory air, water, earth, and fire were the four elements that made up the universe and the human body. Water was moist, air was dry, fire was hot, and earth was cold.

The human body was a microcosm of this scheme, and its corresponding fluids, or humors, were in combinations of two. Blood was warm and wet; black bile, cold and dry; yellow bile, warm and dry; and phlegm, cold and wet.

When the fluids were in balance, health abounded. When skewed, disease resulted. Ancient Greek physicians recognized that discharges from various organs resulted from trauma or sickness. The amount of training of Greek physicians varied because no medical schools, standards, or examinations existed.

A doctor often apprenticed to a more experience practitioner before practicing on his own. In addition to sole practitioners there were public physicians, medical officers elected in some cities. There were also clinics for the less affluent called jatreia.

Aristotle (384–322 b.c.e.) contributed much to Greek medicine. He was interested in many areas of knowledge, but logic was one of his favorite mental exercises. He began to categorize living things into groups with similarities and wrote extensive compendiums on plants and animals. This was the basis for biology and anatomy.

Unfortunately, he did not see the interior of a human body because dissection was not practiced. Although Aristotle contributed much to medicine, philosophy, poetry, literature, and early science, it was Claudius Galen—often referred to as simply Galen—whose writings influenced generations of physicians and whose influence continued well into the Renaissance.

Galen was born in Pergamon to an architect father, who had a dream in which Asclepius appeared and told him to have his son become a healer. By the age of 21 he had written a textbook on the uterus for midwives, a book on ophthalmology, and three books on lung disease. Unfortunately, he did not know very much about the uterus because he had only seen a pig’s uterus and that was quite different from a human’s.

When he was 32, he went to Rome where he established a practice despite his criticisms of his peers there. He was fortunate to be called to the imperial palace to treat Marcus Aurelius, the emperor, whom he pleased. From that time forward, the most prominent members of society sought him.

After Galen accepted Christianity, the church endorsed him because Galen saw a purpose in every organ and every function, and that purpose was divinity. He taught that the body was an instrument of the soul.

Religion and medicine were more closely related in early medicine, and there was often confusion over the place of the soul in the human body. One idea was that it was somewhere between the brain and the spinal cord in a structure called the rete mirable.

The other imaginary structure was the lux bone, a bone that could create an entirely new individual if found. Interestingly, this concept could describe stem cells. Galen also had ideas about the sexes. He believed that since humankind was the most perfect of all animals, within humankind, man was more perfect than woman.

Since a woman’s reproductive parts were formed when she was still being formed, they could not emerge from her body like a man’s because she did not have enough heat to allow them to do so. Despite his errors, his contributions were many, the greatest being a 22-volume set of summarized medical knowledge including medicinal plants.

Galen’s reputation lasted longer than any other Greek physician’s. He codified all previous knowledge and was so valued for this gargantuan task that his stature as a great physician grew with each successive generation. It was not until 1564 that Vesalius, a Renaissance anatomist who performed autopsies and dissections on humans, challenged his writings.

The Greek and, later, Roman physicians lost prestige as the Roman Empire collapsed, the Middle Ages began, and plagues and epidemics destroyed populations in record numbers, leaving people again dependent on superstition and mysticism. Muslim physicians led the way for the next 1,000 years.