Galen

Galen (born 129 ce, Pergamum, Mysia, Anatolia [now Bergama, Turkey]—died c. 216) was a Greek physician, writer, and philosopher who exercised a dominant influence on medical theory and practice in Europe from the Middle Ages until the mid-17th century.[1] Galen was a Greek who became the Roman Empire's greatest physician, authoring more books still in existence than any other Ancient Greek: about 20,000 pages of his work survive.[4]

Early Life and Education

The son of a wealthy architect, Galen was educated as a philosopher and man of letters. His hometown, Pergamum, was the site of a magnificent shrine of the healing god, Asclepius, that was visited by many distinguished figures of the Roman Empire for cures.[1] His father, Aelius Nicon, was an architect and builder with an interest in mathematics, logic, and astronomy and a fondness for exotic mathematical and literary recreations. His mother, according to Galen himself, was a hot-tempered woman, always arguing with his father; Galen compared her to Socrates' wife Xanthippe.[2]

In 144 or 145 Asclepius intervened. In a dream, Galen says, the god told Nicon to allow his son to study medicine, and for the next four years Galen studied with the distinguished physicians who gathered at the sanctuary of Asclepius.[2] When Galen was 16, he changed his career to that of medicine, which he studied at Pergamum, at Smyrna (modern İzmir, Turkey), and finally at Alexandria in Egypt, which was the greatest medical centre of the ancient world.[1]

In 148 or 149 Nicon died, and Galen at 19 found himself rich and independent. He chose to travel and further his medical education at Smyrna (modern Izmir), Corinth, and Alexandria.[2] When Galen's father died, Galen traveled to Egypt (Alexandria) where he lived for perhaps five years (152-157).[5]

Career as Physician to the Gladiators

After more than a decade of study, he returned in 157 ce to Pergamum, where he served as chief physician to the troop of gladiators maintained by the high priest of Asia.[1] He became physician to the gladiators of the Temple of Pergamon's High Priest. According to Galen, his four years in this practice enabled him to learn even more about medicine. The relationship between diet and health is not only a recent issue: Galen identified the importance of a healthy diet for the well-being of the gladiators in his care. He thought of the gladiators' wounds he treated as 'windows,' allowing him to see the functions of various parts of the body.[4]

Career in Rome

Never marrying, Galen eventually left Pergamon in 162 CE to pursue a career in Rome.[3] In Rome, he gave a number of public anatomical demonstrations using pigs, monkeys, sheep, and goats.[3] In Rome, Galen's ambition got the best of him with the result that his high profile created powerful enemies who caused him to depart secretly in 166.[5]

In 168–169, however, he was called by the joint emperors Lucius Verus and Marcus Aurelius to accompany them on a military campaign in northern Italy. After Verus' sudden death in 169, Galen returned to Rome, where he served Marcus Aurelius and the later emperors Commodus and Septimius Severus as a physician.[1] He was the personal physician to Rome's Emperors for decades.[4]

Medical Theories and Contributions

The Four Humors Theory

While he criticized many of his contemporaries, he embraced the ideas put forth by the Greek physician and theorist Hippocrates (460-370 BCE), primarily his concept of the four humours that controlled the human condition: blood, phlegm, black bile, and yellow bile.[3] Building on earlier Hippocratic conceptions, Galen believed that human health requires an equilibrium between the four main bodily fluids, or humours—blood, yellow bile, black bile, and phlegm. Each of the humours is built up from the four elements and displays two of the four primary qualities: hot, cold, wet, and dry. Unlike Hippocrates, Galen argued that humoral imbalances can be located in specific organs, as well as in the body as a whole. This modification of the theory allowed doctors to make more precise diagnoses and to prescribe specific remedies to restore the body's balance.[1]

It was Galen who, in the first century AD, concocted and treated with medicinal herbs and compounds. "Polypharmacy," says history-of-medicine scholar, Robert Hudson, "was Galen's legacy.[12]"

Anatomical Studies and Discoveries

Galen regarded anatomy as the foundation of medical knowledge, and he frequently dissected and experimented on such lower animals as the Barbary ape (or African monkey), pigs, sheep, and goats.[1] Notable also were his vivisection experiments, such as tying off the recurrent laryngeal nerve to show that the brain controls the voice, performing a series of transections of the spinal cord to establish the functions of the spinal nerves, and tying off the ureters to demonstrate kidney and bladder functions.[1]

Galen was seriously hampered by the prevailing social taboo against dissecting human corpses, however, and the inferences he made about human anatomy based on his dissections of animals often led him into errors. His anatomy of the uterus, for example, is largely that of the dog's.[1] Galen was the first physician to use the pulse as a sign of illness.[6]

Physiological Theories

In his life-sustaining schema, the venous, arterial, and nervous systems, with the liver, heart, and brain as their respective centers, were separate, each distributing through the body one of three pneumata: respectively, the natural, the vital, and the animal spirits. He saw blood carried both within the venous and arterial systems, which communicated by invisible "anastomoses," but circulation eluded him.[6]

Literary Output and Scholarship

He wrote over 600 treatises, of which less than one-third exist today.[6] What remains, however, is enough to establish his reputation as the most prolific, cantankerous, and influential of ancient medical writers. His extant works fill some twenty volumes in Greek. Other works survive only in Arabic or medieval Latin translations.[2]

Galen's works fall into three main categories: medical, philosophical, and philological. His medical writings encompass nearly every aspect of medical theory and practice in his era. In addition to summarizing the state of medicine at the height of the Roman Empire, he reports his own important advances in anatomy, physiology, and therapeutics.[2]

Influence and Legacy

Medieval Period

His authority in the Byzantine world and the Muslim Middle East was similarly long-lived.[1] Learned medicine in the Arabic world thus became heavily based upon the commentary, exposition, and understanding of Galen. Galen's influence was initially almost negligible in western Europe except for drug recipes, but from the late 11th century Ḥunayn's translations, commentaries on them by Arab physicians, and sometimes the original Greek writings themselves were translated into Latin. These Latin versions came to form the basis of medical education in the new medieval universities.[1]

Galen's ideas dominated Western medical thinking from his era until the Renaissance. His strongly theistic attitudes were embraced by the Christian thinkers who began to prevail over the affairs of the later Roman Empire. Early Christian writers from the second to the fourth centuries c.e., such as Tertullian, Lactantius, Nemesius, and Gregory of Nyssa, integrated Galen's ideas into many of their works.[21]

Unfortunately, Galen's numerous medical treatises (more than four hundred) were often summarized and distorted by other, inferior, writers, and the Galenism that dominated Western medical thinking from the Dark Ages through medieval times was often far removed from Galen's original writings.[21]

Renaissance and Decline

From about 1490, Italian humanists felt the need to prepare new Latin versions of Galen directly from Greek manuscripts in order to free his texts from medieval preconceptions and misunderstandings. Galen's works were first printed in Greek in their entirety in 1525, and printings in Latin swiftly followed. These texts offered a different picture from that of the Middle Ages, one that emphasized Galen as a clinician, a diagnostician, and above all, an anatomist.[1]

Paradoxically, this soon led to the overthrow of Galen's authority as an anatomist. In 1543 the Flemish physician Andreas Vesalius showed that Galen's anatomy of the body was more animal than human in some of its aspects, and it became clear that Galen and his medieval followers had made many errors. Galen's notions of physiology, by contrast, lasted for a further century, until the English physician William Harvey correctly explained the circulation of the blood.[1]

The renewal and then the overthrow of the Galenic tradition in the Renaissance had been an important element in the rise of modern science, however.[1] His thoughts on the humoral theory and even glaring errors he made in his understanding of human anatomy went completely unchallenged for 1,400 years. In the latter cases, medieval scholars who performed their own dissections were forced to conclude that human anatomy must have changed since Galen's era rather than admit the possibility that the great man might have been wrong. But Galen would have been the first to challenge his own beliefs, writing: "I will trust no statements until I have tested them for myself," and concluding: "the surest judge of all will be experience alone."[7]

Death and Historical Assessment

Galen's final works were written after 207, which suggests that his Arab biographers were correct in their claim that he died at age 87, in 216/217.[1] For over a thousand years after his death, Galen, with his prodigious accomplishments, was considered to be the gospel truth, the ultimate authority on all matters medical. Medieval medical authorities dogmatically agreed: If Galen figured it all out, why look any further? This was indeed to prove a mixed blessing for the history of medicine. It wasn't until the Renaissance that Galen was finally questioned and his errors uncovered.[10]