Early practices

     Homer’s “Iliad” and “Odyssey” and Hesiod’s writings provide the only insight into early Greek medicine. In these works diseases are of divine origin. Homer mentions wounds and their treatments, healing incantations, pharmaceutical remedies, some of Egyptian origin. Physicians are portrayed as professionals who practiced healing arts as a full time occupation.

     Preistly healing was a prominent medical practice during 4^th - 3^rd century B.C. Asclepius was the God of medicine. Homer referred to him as “the great physician”. Priests in the temples to Asclepios used therapeutic processes such as dream healing, bathing, sacrifices, prayer, dietary restrictions and exercise. They emphasized the importance of suitable offerings to the gods. These practices remained significant well into the Roman period.

     In the ancient times there were other healing practices as well. Traditional practitioners of medicine included midwives, herb-gatherers, bone-setters on top of various priestly healers. Alongside them existed the more learned physicians. This does not mean the various practices did not mix. There were no formal schools of medicine. Physicians learned their profession through apprenticeships. What they learn would depend largely on their mentor, but also on any major influences of the time or area.

Hippocratic medicine

     From the 5th and 4th centuries BC come a collection of 60-70 loosely connected medical writings attributed to a man known as Hippocrates of Cos (460-370 BC). From these we can gain a glimpse into the more learned medical profession of the times. Hippocratic writings regarded relationships between nature and causes of disease. They established standards to drive our charlatans and enhanced a physician’s image and prestige as a healer.  Ethical concerns are also relfected - the Hippocratic oath comes from these writings.

     The Hippocratic treatises associated disease with imbalance in the body or interference with its natural state. “On the nature of man” contains a theory that the body is composed of four humors: blood, phlegm, yellow bile, black bile, and that disease was caused by an imbalance between these humors. Therapy was directed at restoring balance. It constituted diet, exercise and purging of the body. Special attention was given to seasonal and climatic conditions and natural dispositions of the patient. The humors themselves were linked with seasons: phlegm with winter, blood with spring, yellow bile with summer, and black bile with autumn. They were also associated with a pair of properties: wet/dry and hot/cold. For example, phlegm was cold (dominates in winter) and wet, while blood was hot (vital force was associated with heat) and wet - so it was thought responsible for fevers.

     The sharply reduced presence of supernatural explanations is remarkable. Invoking a devine element in the explanation of a disease was even seen as a sign of failure. The causes of disease were expected to act uniformly, universaly - the human body was the orderly universe of the Hippocratic physician.

      The practice of Hippocratic medicine shows many similarities to today. The foremost task of the physician was to give advice on how to keep healthy and to assist the natural healing processes in case of illness. In case clinical aid was necessary, a patient would be thoroughly examined, including eyes, face, hands, posture, breathing, sleep, stool, urine, vomit and sputum (material ejected from the mouth). The physician would look for coughing, sneezing, hiccupping, flatulence, fever, convulsions, pustules (small, inflamed, pus-filled bumps on the skin), tumors or lesions. Very detailed case studies existed with precise and clear descriptions of symptoms and their evolution in time. This made diagnosis and prognosis possible. Explaining the course of the disease was in many cases the most anyone could expect. Medicines such as laxatives, emetics (to induce vomiting), narcotics, expectorants (to promote coughing), plasters, salves, and powders existed for the treatment of many illnesses, but the there was no known treatment for many others. The most skill an ancient physician could show was with treating wounds, fractures and dislocations. The knowledge of in such cases was admirable even by today's standards.

Hellenistic Anatomy and Physiology

     Hippocratic knowledge of anatomy and physiology seems to have been limited. There is little evidence of human body dissection, perhaps due to various religious taboos. Therefore, the only knowledge of human anatomy came from animal dissections and clinical practices such as surgery.

     The practice of human dissection began in Alexandria during 3^rd century B.C. Details of its origin are unknown.  It was presumably made possible by the Ptolemaic dynasty which held enough power to surpass social taboos. Herophilus of Chacedon and Erasistratus of Ceos were the first to engage in systematic dissection of the human body. A Roman encyclopedist Celsus and a church father Tertullian have engaged in vivisection of prisoners.

Herophilus

     Herophilus was a pioneer anatomist who studied medicine under Paraxagoras of Cos in his native Asia Minor and then moved to Alexandria to continue his career. His main focus was structure. He studied the brain, the nervous system, the eye and the abdominal cavity. He identified two of the brain’s membranes: dura mater and pia mater. He traced connections between the brain, spinal cord and nerves. He distinguished sensory and motor nerves. He studied the eye identifying and naming its parts. He described the liver, pancreas, intestines, reproductive organs and heart. He investigated ovaries and fallopian tubes and wrote treatises on obstetrics. He distinguished arteries and veins by the thickness of their walls. He examined the valves of the heart. He began using pulse as a diagnostic tool. 

Erasistratus

     Erasistratus studied medicine in Athens. Contrary to Herophilus, he was very interested in organ function therefore his work is of a physiological nature.  He described the bicuspid and tricuspid valves of the heart and their function. He noted the one way flow of blood through these valves. Erasistratus explained that the heart worked like a bellow, expanding to draw blood and pneuma inside and then contracting to expel blood into veins and pneuma into arteries.

     Erasistratus was influenced by the peripatetic school. He believed in an atomist philosophy developed by Strato, where any material object was composed of tiny particles and void space. According to Erasistratus, all tissue in the body contains veins, arteries and nerves that serve as channels to transport fundamental substances to various organs. Food would travel to the stomach, where by various processes it would be turned into a 'juice' of sorts. The juice would escape through pores in the stomach and intestine to the liver, where it was further processed and turned to blood. The blood would then travel through veins to provide nourishment for the body. In the case of respiration, a vein-like artery would carry pneuma (animating warm air) from the lungs to the left side of the heart, where it was pumped to the rest of the body. Pneuma was responsible for the vital capacities. A different pneuma would travel from the brain throughout the nerves. This was psychic pneuma responsible for sensations and motor function. Erasistratus thought the processes of transporting the blood and pneuma were mechanical. Nature abhors vacuum, he argued, and so the use or wastage would force new material to come in.

     Theories of disease can be created from Erasistratus' physiological models. He considered for example that overeating would create too much blood in the body. This would lead to overflows in some areas and inflamation and fever would follow.

Hellenistic medical sects 

     The field of medical practice was not a coherent one, as mentioned earlier. Different physicians could have diametrically opposed philosophies on the practice and development of medicine. From the surviving discourse a few medical sects with more or less similar opinions can be formed.

Rationalists or dogmatists - committed to speculative, theoretical medicine; attempted to merge medicine with natural philosophy; believed learning anatomy and physiology through human dissection was important for the practice of medicine; searched for hidden causes of disease.

Empiricists or skeptics - strongly opposed speculative and theoretical medicine and considered physiological theories a waste of time; believed that medicine should be practiced based on case histories.

Methodists - appeared in 1^st century A.D. in Rome; believed disease depended on tenseness and laxness of the body.

Pneumatists - built a medical philosophy based on Stoic principles.

Asclepiades of Bithynia - replaced humoral theories with atomist ones.

Galen

     Galen was a medical scholar who was born in 129 A.D. in Pergamum. He decided to persue a medical career at sixteen and traveled to different cities in order to learn what he needed. Eventually he would become the physician to such people as gladiators and emperors. During his lifetime he wrote a large amount of medical literature. His medical authority was rivaled only by that of Hippocrates. His findings were very persuasive, and he remained an authority on medical issues through the middle ages and into the early part of the modern period. Part of his popularity came from Christians and Muslims, who found the spiritual implications within his work appealing. Galen was heavily influenced by Plato, Aristotle, the Stoics, and by Herophilus and Erasistratus. He was an eclectic (selecting from various doctrines) rationalist, and often used his patients as vehicles in his study of diseases.

     Galen compounded earlier medical knowledge, clarified it made it compatible with philosophic principles of the time. He kept the humors, which became the elements composing tissues. From the tissues were made the organs and from these the body. This made localization of disease possible. For example, a general fever would be caused by a putrefying (decaying) humor in general, where a localized fever would imply an imbalance of humors in a specific organ, which would swell or harden and cause pain.

     Human dissection was again impossible in Galen's time. He based his anatomical work "On Anatomical Procedures" on analogy with animal dissection. This led to the mistake of identifying the rete mirabile, which exists only in some animals. Even with such mistakes, this work remained the only anatomical work until the Renaissance.

     Borrowing from Plato and Erasistratus, Galen created three physiological systems, which were interconnected. The brain (seat of the rational soul) was responsible for sensations and motor functions received through the nerves containing psychic pneuma. The heart (seat of passions) distributed arterial blood containing vital pneuma throughout the body. The liver (seat of desire and appetite) was the source of venous blood, which provided nourishment.

Venous system. According to Galen's physiological model, food would enter the stomach, where mechanical processes and cooking in the body's heat would transform it to chyle. The chyle would then be drawn into the mesentary veins through pores in the intestines and carried to the liver. In the liver, chyle would be refined to form venous blood which would be distributed to all parts of the body (including the heart) through veins.

Arterial system. Some of the venous blood that entered the vena cava (right side of the heart) would be drawn through the pores in the interventricular septum to the left ventricle of the heart. Here it would be vivified by the innate heat in the heart and mixed with pneuma. This mixture would then leave the heart in the form of arterial blood and be distributed throughout the body by arteries. The innate heat of the heart was kept through the burning of air exchanged with the lungs via the vein-like artery. As the heart expanded air (pneuma) would be drawn in, and as it compressed the "soot and smoky vapors" (Lindberg) would be expelled into the lungs (all through the vein-like artery).

Nervous system. Galen incorrectly attributed the rete mirabile to humans. He supposed that arterial blood delivered to the brain would also flow into the rete mirabile (dense network of blood vessels) and be refined there into phychic pneuma. The psychic pneuma would then flow through the nerves.

     The association of life and vital force with heat Galen derived from Plato and Aristotle among others. For the functioning of the body the right degree of vital heat was critical, and the source of this heat was the heart. The lungs became the means of moderating the heat (the lungs surround the heart) and nourishing the fire within the heart. Galen did not believe the pumping action of the heart was enough to explain the movement of fluids through the body. He thought the organs attracted or repelled the substances as necessary (the liver would draw chyle for example).

     Galen's approach toward medicine was teleological. He believed nature does nothing in vain and so attributed a purpose to every part of the human body. He summed up medical achievement and fitted it into the dominating philosophical and theological framework. His work On the Usefullness of the Parts of the Body contains a litany of praise to the wisdom and providence of the Demiurge (Lindberg p.130). This and other views made him popular with Christians and Muslims, who dominated the philosophical discussions through the Middle Ages.

Key terms and definitions

humors -  elements of the human body. They were blood, phlegm, yellow bile and black bile

pneuma - warm air with animating properties

References

Lindberg, David C. The Beginnings of Western Science : The European Scientific Tradition in Philosophical, Religious, and Institutional Context, Prehistory to A. D. 1450. New York: Chicago U.P, 2008.