Recount the development of Greek medicine, theoretical and practical, from the Hippocratics to Galen, and relate these developments to Greek philosophy generally. Describe the different epistemological approaches to understanding the nature of the human body.
While much of today's advances of modern medicine have come from within the last century, the methodological and philosophical framework began centuries ago in Ancient Greece. The beginnings of Ancient Greek medicine are rooted in superstition and religious healing with little in the way of empiricism or any formal ethical doctrine. As writing and philosophy became more prevalent in Greek society, the now modern views on medicine were born as medicinal experimentation and documentation proliferated through Greek society lending a steady logic and increasing body of works from which later practitioners could learn from and build on. A group of learned practitioners named the Hippocratics produced the largest corpus of early documentations on a vast array of subjects within medicine. Three distinct schools of thought formed around how to practice medicine emerge from their writings: Empiricists (who relied almost strictly on observation), Dogmatists (who stressed theory and philosophy), and Methodists (who viewed the body holistically with a little theory and observation). These schools would inform later scholars of the Hellenistic period who blurred the lines between empiricism and philosophy. The culmination of this progression is with Galen, long considered the apex of Greek medicinal thought and practice, who insisted that rational theories and philosophies about the body and diseases must be corroborated by empirical research. Galen's accomplishments erased any need for past influence and controlled the direction of medicine in the western world until the 18th century.
Ancient Greek medicine had no established standards prior to Hippocratic writings. These writings began as a collection of 60-70 loosely connected medical writings which are attributed to a man identified as Hippocrates of Cos (460-370 BC), but may not have been all produced by him. These writings provide valuable information about the learned medical profession of Ancient Greece. The writings include theories of health and diseases, treatises on anatomy and surgery, case histories of illnesses and ethical studies, including the famous Hippocratic Oath. The purpose of these writings was to address a recognized need to create standards and drive out charlatans from the profession. The physicians whose views these writings reflect are called the Hippocratics.
The Hippocratics believed that the foremost task of a physician is to prevent ailments from affecting a client through lifestyle advice, or assisting in the natural healing process if the disease had already struck. The advice given by a physician would include suggestions about food, diet, exercise, sexual activity, etc. A proper regimen (diet and exercise), it was thought, would help bring a patient back to health. In some cases, however, the physician would give clinical aid as well. Aside from simply giving preventative healthcare, physicians gave diagnosis of an ailment allowing the suggestion of a treatment. The prescribed treatment would vary according to the type of disease, how widespread it was, and the symptoms. A physical regimen for the patient would certainly be suggested, but internal and external medications were also available. These medicines included laxatives, emetics (to induce vomiting), narcotics, expectorants (to promote coughing), salves (ointments), plasters, and powders. These treatments had various outcomes, but most diseases had no cure. The physicians had the most skill with wounds, fractures, and dislocations.
In the case that a physician would treat a patient, four major steps of treatment were carried out: examination, diagnosis, prognosis, and treatment. The examination of a patient was very thorough. According to the writings, a physician should examine: the eyes, face, hands, posture, breathing, sleep, stool, urine, vomit, and sputum (matter ejected from the mouth). We would probably recognize these from modern examinations as well. They were looking for such symptoms as: coughing, sneezing, hiccupping, flatulence, fever, convulsions, pustules (inflamed swellings of the skin), tumors or lesions. A physician could then compare these observations with case histories of various ailments and identify the disease. Case histories existed for many diseases which ravaged the population and were characterized with much precision and clarity. The environment was also an important factor to take into account when considering the health or ailment of an individual. Different illnesses would be expected depending on the temperature or season, for example. Once the disease was identified, it was also possible to make a prognosis on the course of the disease based on these histories.
It is worth noting here, that there was a sharply reduced presence of supernatural explanations for diseases. The Hippocratic text On the Sacred Disease notes: "By invoking a divine element they were able to screen their own failure to give a suitable treatment..." Clearly the Hippocratics thought that every disease has a natural cause. Any other approach would deem someone unfit to be called a physician. The case histories might gather another similarity with the early philosophers. If these histories are seen as useful, then clearly the Hippocratics believed that the causes of disease are uniform and their course universal. One might go further and say the human body was to the physicians what the universe was to the philosophers – an orderly being which can be understood.
When it came to understanding the orderly body among the Hippocratics, the practicioners fell into two distinct camps: Skeptics and Speculators. The Skeptics' approach was based on former experience and they would accept causal theories only if they were supported by overwhelming evidence. They were generally not interested in any theories about the "hidden" causes of illnesses since these causes could not be observed. Skeptics felt that a physician should focus on known, observable causes, and reliable, documented methods of treatment. They were the equivalent of the early empiricists in the philosophic domain. The Speculators thought philosophy could be used to serve the medical profession. They searched for a theory of diseases, which would include their hidden causes. One of these theories is influenced by the four element theory prominent in the philosophical discussions of the day. The health of an individual depended on the balance of four substances: blood, phlegm, yellow bile and black bile. These in turn were pairs from the properties of hot/cold and wet/dry, and the parallels to fire, air, water, and earth are plain to see. A disease would be characterized by an imbalance of these four bodily humors and manifest itself as an excess of one of the properties. In this we can see a thought similar to Aristotle and his four element theory. The similarities do not end here. As mentioned earlier, the physician's primary task was to assist the natural healing process. Since health was the natural state of the human being, the imbalance brought about in the human body would tend to correct itself. This is why the techniques thought most useful would be proper regimen and various purgatives – to ensure the cause of imbalance is removed and that it is not introduced again.
A stumbling block to Hippocratics when understanding the human body was their limited access to cadavers. Their knowledge of anatomy and physiology was extremely limited as dissection of human bodies was essentially dishonor and sacrilege. Therefore, whatever knowledge of human anatomy the hippocratics had came from animal dissections and surgery and other clinical practices. Practice of human dissection began in Alexandria during 3rd century B.C. and was presumably assisted by royals of Ptolemaic dynasty who held enough power to surpass social taboos. Contemporary medical advancements, new social standing toward medicine, integration of medicine and philosophy could also have assisted this new development. Herophilus of Chacedon and Erasistratus of Ceos were the first to engage in systematic dissection of the human body. Roman encyclopedist Celsus and a church father Tertullian engaged in vivisection of prisoners.
As time passed, Greek culture began to be subsumed by Roman culture (though they largely borrowed from the Greeks) as the Roman empire grew. The Roman empire grew, yet our knowledge of Hellenistic medicine during the this period is miniscule at best due to a lack of manuscripts. This is largely attributed to the last great medicinal scholar Galen, as he eclipsed all those before him. Yet he left enough information about his influences that the path of Greek medicine can still be traced through the Hellenistic period. It is important then to take a closer look at two of Galen's biggest influences, Herophilus and Erasistratus, to gain a better picture of the continued transformation Greek medicine would take in its tangled path with natural philosophy.
Herophilius is perhaps the first (according to sources) to make major breakthroughs within the study of human anatomy. He studied the brain, the nervous system, the eye and the abdominal cavity extensively. He identified two of the brain’s membranes; dura mater and pia mater and traced connections between the brain, spinal cord and nerves. He distinguished sensory and motor nerves and studied the eye identifying its parts and principal humors and tunics. He traced the optic nerve from the eye to the brain and argued that it was filled with subtle pneuma. 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 valves of the heart. He investigated the arterial pulse and used pulse variations as diagnostic and prognosis tools. Herophilius was mostly interested in structure rather than function, but his relative contemporary Erasistratus had a more physiological view.
Erasistratus furthered the work of Herophilius. 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 arteries and pneuma into veins. This function is due to an innate facility residing within the heart, he further described. He believed a theory similar to Corpuscularianism that said matter is consisted of tiny particles separated by minute void spaces. He combined this theory with the theory of pneuma to explain physiological process such as digestion, respiration and vascular system.
According to Erasistratus all tissue in the body contains veins, arteries and nerves that serve as channels to transport fundamental substances to various organs. He explained digestion as food enters the stomach, it is converted to juice and then this juice travels through tiny pores in the stomach to the liver where it is converted to blood. Veins carry blood to parts of the body. Erasistratus described that arteries only contain pneuma, which is inhaled from outside and then taken to left side of the heart with a vein-like artery and the heart distributes pneuma via arteries throughout the body. He described that nerves contained a different type of pneuma called “psychic” pneuma which is formed from arterial pneuma in the brain and produces sensation and motor functions. He believed the blood vessels functioned through vacuums. His theory faced a strong objection that when an artery is cut, blood flows out. Erasistratus debated this opposition by explaining that when an artery is opened it can create a vacuum and this vacuum opens up tiny channels between arteries and veins allowing blood to temporarily pass from veins to the arteries and flow out the wound with the pneuma.
Erasistratus’ theories of vascular flow and nutrition led to a general theory of disease. Erasistratus believed that disease was cause by excessive blood in veins due to excessive eating. He argued that when veins contain excessive blood the extra potion enters the arteries through normally closed channels and flows to body parts where it causes fever and inflammation. He described the cure was to reduce the amount of blood by reducing eating and sometimes bloodletting.
Herophilus' and Erasistratus' impact upon the medical world was large and grew after their deaths. With writing and scholarship becoming increasingly more pronounced with the present society, their experiments and theories were published and circulated widely. Their influence was felt far and wide as many physicians and scholars took up the medical scions' arguments and began expounding upon them while attacking others. The ever increasing dialogue throughout the Hellenistic world lead to the formation of several schools of thought: the Empiricists, the Dogmatists, and the Methodists (not to be confused with a much later sect of Christianity). Empiricists argued that observation was key, that past experience was doubtlessly important, and that theoretical speculation as to any hidden causes was moot because there were never hidden causes. Human dissection to them was both tactless and pointless. They were essentially traditionalists harkening back to methods of practice pre-Herophilus and Erasistratus. The Dogmatists, or Rationalists, argued otherwise suggesting that theoretical speculation about what goes on inside the body is a valuable pursuit and is greatly aided by human dissection. Again, the precursors to these groups can be seen in the Skeptics and Speculators of the Hippocratic era, who were divided on the same basic issue. While they continued the application of natural philosophy to the medical field, they often differed in how to interpret or even how to carry on the works and ideas of Herophilus and Erasistratus. The Methodists appeared only a couple of hundred years later in the 1st century AD and contended with both previous schools that they had made things far too complicated. The focus of the origin of disease should be on the laxness and tenseness of the body, not in empirical observation or any sort of speculation due to observation from dissection. Everything could be related to the pores in your body. Quite simply, if the pores were clogged than you were sick and the pores must be unclogged to allow the free flow of atoms in and out of the body.
It was Galen then who would build from all of these methodologies and subsequently nullify all of them with the creation of his own. Galen was a medical scholar who was born in 129 AD in Pergamum. He decided to pursue a medical career at age sixteen and traveled to different cities so he could learn his craft. He was physician to gladiators, and to the emperors Marcus Aurelius, Commodus, and Septimius Severus. During his lifetime, he wrote an enormous body of medicinal literature, and his medical authority was rivaled only by that of Hippocrates. His findings were also very persuasive, and they would dominate medical thought and teaching throughout the Middle Ages and into the modern period. Part of what gave him such authority was his popularity among Christian and Islamic people, who found the spiritual implications, specifically the evidence of a creator, within his work appealing. His work was heavily influenced by that of Plato, Aristotle, the Stoics, and by Herophilius and Erasistratus. He was an eclectic rationalist, and often used his patients as vehicles for the study of disease.
Galen's teleology informs his views on why the body works as it does. He stressed the Platonic idea that a creator designed the body and all of its parts for a specific purpose, even borrowing Plato's term "demiurge." Each organ, rather than functioning in a mechanistic push/pull system, functioned as living devices which had needs that were fulfilled by the influx and decrease of fluids. All of the organs then have their needs fulfilled by the borrowed notion of the tripartite soul, again from Plato. Galen believed that the four humors, blood, phlegm, yellow bile, and black bile, where the fundamental components that made up the body. These four humors came together to form tissues, which in turn formed organs, and these organs unite to form systems that make up the body. It was important that these humors remained in proper balance, because an imbalance in the humors is what leads to illness. For example, generalized fevers are produced throughout the body by the heat of putrefying humors, and localized fevers result from noxious or toxic humors within a specific organ, leading to changes such as hardening and swelling, and thus pain. To diagnose illness, Galen relied greatly on pulse and urine samples. Galen also surmised that the brain, the heart, and the liver all contained three separate parts of the soul and each of which played a direct role in the functioning body. The brain was posited to be the source of the body's nerves and also the locus of thought and rationality, and it emitted a psychic pneuma.
During Galen's time, the practice of dissecting humans was greatly opposed; and it led Galen to turn to animals with human-like anatomies for dissection. Unfortunately, this caused him to make a few wrong assumptions about the human body, the most famous of which the assumption that humans have a rete mirabile, which they do not. The rete mirabile is a network of fine arteries located in the necks of some animals to serve the function of keeping them cool. Galen believed that in humans, the rete mirabile purified blood to such a refined state that it became psychic pneuma, and this psychic pneuma was sent throughout the body and accounted for sensation and motor functions. The heart was the source of the arteries and arterial blood, giving life to passions within a person, which is called vital pneuma. Lastly, the liver was the source of the veins and venous blood as well as desire or appetite. The body's design was such that each of these parts played a direct role in nourishing the other as well as the rest of the body. Thus each part of the anatomy functioned for a specific purpose.
From the beginning of learned, institutionalized Greek medicine and the Hippocratics to Galen, the practice of medicine changed considerably. Supernatural causes of disease were largely replaced by natural causes that were observable if not always treatable. Physicians became more unified, belonging to one school of thought or another, sharing ideas and debating. Whether they believed in empirical observation and diagnosis or in developing an anatomical/physiological theory, there was clearly a distinct method being utilized in each of their practices. This time period eventually saw the beginning of human dissection and the development of medical theories about the functions of parts of the body that would last for centuries.
BIBLIOGRAPHY
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.
Cohen & Drabkin. A Sourcebook in Greek Medicine.