Galen of Pergamum: Ancient Rome’s Great Philosopher Physician

In today’s modern world, we tend to think of life in ancient times as an unrefined place inundated with disease, poverty, and crime. While these problems did exist, if we could transport ourselves back in time 2000 years to ancient Rome or Alexandria, Egypt, we would discover that these cities were far more sophisticated than we previously might have imagined. Several cities before and during the first and second centuries CE were centers of culture, education, science, engineering, architecture, art, and economic growth — particularly Alexandria, in Egypt, and Pergamum, in Anatolia (present-day Turkey).Of all the physicians practicing medicine during the period, one man stands out above all the others. His name was Claudius Galenus, often referred to as Galen.

Although Greek, Galen was Born in 129 CE in the Roman/Asian/Greek city of Pergamum. In his lifetime, Galen would become the most influential and esteemed physician and medical researcher in the Roman Empire.

Galen’s father, Aelius Nicon, a wealthy well-respected architect and builder with interests in mathematics, astronomy, philosophy, logic, and Greek literature, was fully invested in his only son’s early education. He expected Galen would study philosophy and politics along with his formal studies; traditional pursuits of the wealthy, culturally sagacious class into which Galen was born. However, with his father’s guidance, at the age of 14, he began his studies in mathematics and philosophy. His education also included an examination of the four major philosophical schools of the time: the Platonists, Peripatetics, Stoics, and Epicureans.

Galen’s father emphasized the importance of examining differing philosophical and educational perspectives. In his writing Galen noted that the most significant principle his father taught was “to follow no one sect but to hear and judge them all, to despise honor and glory, and to magnify truth alone.” This principle above all else clearly influenced Galen’s philosophical and scientific positions throughout his life.

Homo Universalis

When Galen was 15, his father had a dream in which the God Asclepius, the Greco-Roman god of medicine, urged that Galen study medicine. Accordingly, at the age of 15, Galen began his formal medical education, and for the next four years, he studied at the esteemed sanctuary dedicated to Asclepius (the Asclepieum) located in his home city of Pergamum.

Galen was influenced early on by the teachings of the ancient Greek physician Hippocrates (460 BCE – 375 BCE), who had encouraged his students to travel in the pursuit of knowledge. When Galen was 19 years old, his father died and Galen became a rich man. His new wealth allowed him to seek alternative schools of study.

His pursuit of a more holistic education eventually took him to Smyrna (modern İzmir, Turkey), to study anatomy with the doctor Pelops, and to continue his studies in philosophy with the Platonist philosopher Albinus. From Smyrna, Galen traveled to Corinth in mainland Greece, to study natural science, and medicine under the Greek physician Numésian, and finally to Alexandria, Egypt where he studied anatomy for perhaps as long as five years. It was in Alexandria where Galen was finally given the opportunity to examine the human skeleton.

After nearly a decade of studies, in 157 CE, Galen returned to his home city of Pergamum. The following year he accepted a position as the chief physician to the gladiators. He spent the next four years preparing them for gladiatorial combat and treating their horrific, life-threatening injuries. Treating gladiators allowed him the opportunity to discover more about human anatomy. The experience resulted in valuable practical acumen in trauma injuries, physiology, anatomy, and sports medicine.

Flesh and Bones

Galen believed that anatomy was the basis for all medical understanding. But because it was religiously and culturally taboo to dissect humans in the Roman Empire at the time, (human dissection was made illegal in Rome and its provinces in 150 CE), he had no other choice but to dissect other animals for research purposes. He dissected and conducted experiments on both living and dead Barbary Macaque monkeys (Macaca sylvanus), sheep, goats, pigs, dogs, bears, and on at least one occasion an elephant.  He would often give demonstrations of animal vivisection while surrounded by competing physicians. He would ask those observing to name a part for dissection, then operate on the animal and show how the reality differed from known anatomy. During one public demonstration he eviscerated a live monkey and replaced and secured its entrails to the astonishment of spectators and physicians alike.

Anatomical Discoveries

Galen was an astute observer. One of his most significant observations was that arteries carry blood rather than air. He differentiated arteries from veins, described the valves of the heart, and understood the discreet characteristics of seven pairs of cranial nerves. His research into the nervous system resulted in an understanding that nerves transmit information from the brain to various distinct components of the body. Vivisection experiments on pigs resulted in the understanding that the laryngeal nerve is the conduit from the brain that controls the voice. During one public demonstration, when he ligated a pig’s laryngeal nerve, the pig was unable to make any noise.

He also proposed that the primary structures of the eye consisted of a number of distinct membranes and fluids. He differentiated between their disparate structures including, the cornea (the clear outer layer at the front of the eye); the white of the eye known as the sclera; the lens capsule (the transparent membrane covering the entire lens) the retina (the tissue at the back of the eye that reacts to light and transmits signals to the brain); and the structures enveloping the muscles of the eye.

However, he incorrectly believed that blood was formed in the liver, and incorrectly concluded that the blood goes back and forth from the heart in a slow ebb-and flow motion rather than in a circulatory motion. Unfortunately, his incorrect notions about blood and its origin became established medical orthodoxy for centuries.

Having spent a great deal of his adult life studying philosophy. He modeled his studies following a pluralistic paradigm, he repeatedly drew theoretical ideas from earlier philosopher physicians; particularly Herophilus, and Erasistratus. Galen was also influenced by the writings of Hippocrates, who he hoped to emulate. Still, he often amended or incorporated earlier ideas to suit his own research and observations.

Galen was also influenced by the early Greek philosophers, particularly Plato, and Aristotle. Plato’s model of the tri-partite body/soul postulated that the body and soul’s “Rational element” analyzes, and determines options for the most rational outcome of any given situation.  the “Spirited element” represented by the heart requires bravery and supreme honor, and the “Appetite element” is ruled by bodily pleasures such as sexual gratification, and greed for money and food. Additionally, Aristotle’s ideas were significant influences on Galen’s research. He understood and adapted Aristotle’s observations regarding animal classification in anatomy, physiology, and early development (embryology).

The Four Humors

Galen expounded and employed the Hippocratic theory of the four humors (also known as the four temperaments) in his medical practice. Hippocrates’s theory of the four humors proposed that the human body consisted of four major fluids or humors that must be maintained in equilibrium in order to promote health and well-being. The four bodily fluids, were blood, yellow bile, black bile, and phlegm. The humours were closely related to the theory of the four elements: earth, fire, water, and air. Earth being represented by black bile, fire by yellow bile, water by phlegm, while air was allied with blood. The humors were also associated with an individual’s personality;  “Sanguine” people were thought to have the temperament of blood (red), which corresponded to the heart, and was associated with Spring.

A sanguine individual was generally thought to be confident, rational, optimistic, cheerful, and even-tempered, especially in difficult situations. A “Choleric” individual’s personality was characterized by personal ambition, energy, competitiveness, and independence. They were associated with yellow, with the summer season, and with the physical element of fire. A “Melancholic” individual was characterized by black bile and associated with the liver and with Autumn. He or she was often thought to be a “thoughtful ponderer,” kind and considerate, and highly creative.  An individual with a phlegmatic personality corresponded to the fluid phlegm and the Winter season. Phlegmatic individuals were generally thought to be kind, observant, consistent in their decision-making, and relatively composed; characteristics that make them good administrators.

The four humors were thought to require balance for the preservation of the body’s physical and mental health. These four analogous properties provided a model for maintaining overall health through conscious maintenance of the body’s balance via the implementation of remedies to correct imbalance.

These principal points are also “loosely” linked to the Platonic tripartite soul: the logistikon (reason), the thymoeides (spirit), and the epithymetikon (appetite). If the humors of the soul/body are out of balance, the individual becomes ill. In such a case, the physician aids the patient in maintaining balance by first recommending a change in activity, diet, exercise, or rest to correct the imbalance. If these changes fail to remedy the illness, the physician would prescribe a therapeutic intervention.

As an example, if the patient was full of “uncontrollable spiritedness” (emotion), he or she was thought to be suffering from too much blood. This condition would be treated with the use of bloodletting. In the case of fever, it was assumed that the body needed cooling. The patient was then be administered cold drinks, or cold baths to restore balance.

At the age of 32, Galen recognized that practicing medicine in Pergamum would not help him to fulfill his aspirations; Pergamum would not provide the opportunities that his talents and ambitions demanded. With this in mind, he left Pergamum for Rome. In Rome, he gave public lectures, and anatomical demonstrations which quickly led to him becoming a figure of substantial reputation; both good and bad. He was promptly accepted by the social elite of the Roman capital for his capabilities as a physician and teacher. He was also befriended by the Peripatetic philosopher Eudemus and the Roman consul Flavius Boethius who ultimately brought Galen to the attention of the emperor Marcus Aurelius.

However, his criticism of Roman Physicians enraged his rivals; Eudemus warned him he was putting himself in danger of assassination. Fearing for his life, in 166 CE, Galen abandoned Rome for his home city of Pergamum where he once again set up practice and continued with his research. In 169 CE, Galen was summoned to return from Pergamum by Marcus Aurelius to join him in northern Italy where he was in command of the Roman legions engaged in the battle of Aquileia against the “barbarian” Quadi and Marcomanni tribes.

However, a deadly outbreak of the plague prevented Galen from joining the emperor.  In turn, the outbreak of the plague devastated the Roman troops at Aquileia which prompted Marcus Aurelius and his staff to return to Rome.  The emperor again summoned the 40-year-old Galen, this time to Rome where he would spend the remainder of his life. He became physician to the emperor and his family and he would later serve as physician to the emperor Marcus Aurelius’s son Commodus and the future Roman emperor Septimius Severus.

While in Rome, Galen rented and stored many of his personal possessions in a warehouse (the Horrea Piperataria, or Pepper Warehouse) adjacent to the Temple of Peace near the center of Rome. Sadly, in 192 CE a fire broke out which quickly spread to the Forum, the Temple of Vesta, the warehouses adjacent to the Temple of Peace, the Temple of Peace itself, and the imperial palaces on the Palatine. Fire destroyed most of his possessions that were stored there. 

Galen seemed at least outwardly to accept his loss without consternation. He later wrote in his philosophical treatise On the Avoidance of Grief about losing his most prized possessions and he claims that he remained resolute because of his Stoicism; which taught the ability to maintain self-control and emotional strength as a method for overcoming destructive emotions. He not only lost many of his written works, but large quantities of silver, and gold, legal documents, medical instruments that he invented, wax models of instruments that he was developing, and ingredients for medicines used in his practice. Despite his loss, he spent the remaining years of his life continuing to produce major medical and philosophical literary works.

Galen’s Contribution to Medicine

There is no agreed date for Galen’s death. Some scholars suggest that he died in 199 CE at the age of 70 years. Arab scholars, however, have suggested that he may have died in 210 CE.  Others remain confident his death occurred in 216 CE at the age of 87. Regardless, Claudius Galenus is considered one of the most accomplished of all medical researchers of antiquity. Some thought him a genius and polymath. He was a noted physician, philosopher, medical researcher, anatomist, physiologist, pharmacologist, neurologist, nutritionist, writer, pedagogue, and polemicist. The Roman Emperor Marcus Aurelius described him as “Primum sane medicorum esse, philosophorum autem solum” (first among doctors and unique among philosophers).

During the later years of his life in Rome, he produced an enormous body of literary work. From 179 CE until his death, Galen continued his medical research and writing and crafted many of his major treatises on both philosophy and medicine. He produced such major works as his Magnum Opus, The Method of Healing, as well as many philosophical treatises such as, On the Equality of Sin and Punishment, The Slight Significance of Popular Honor and Glory, and The Refusal to Divulge Knowledge.

His surviving scholarly works include 300 titles and more than 20,000 pages much of which was translated into Latin, Syriac, Arabic, and Hebrew. His writings alone compose close to 10 percent of all ancient Greek literature before 350 CE. By 500 CE, Galen’s principles were being taught in Alexandria. In approximately 850 CE, the Arab physician, Ḥunayn ibn Isḥāq with help from his students, composed an annotated list of 129 of Galen’s writings in Arabic. The translated works were used as fundamentals for studying medicine, anatomy, and physiology in the Arabic speaking world until the modern age.

Galen was clearly ahead of his time. Although he didn’t get everything right with his observations, he was a critical player in the advancement of medicine and medical research. His works were translated and handed down to subsequent generations and transformed how medicine and medical research were practiced and taught. He moved the science of medicine forward when it was dominated by mysticism and superstition so that it became a discipline based on observation and empiricism. Galen is arguably the most accomplished of all the medical researchers of antiquity and dominated he medical teaching in both the eastern and western world for nearly 1500 years.