Marcus Aurelius was Roman emperor from 161 to 180 CE and author of the Meditations, a set of Stoic philosophical reflections written during military campaigns. He is significant to medical history primarily for two reasons. First, he was Galen’s most important imperial patron: he appointed Galen as physician to his son Commodus, praised him publicly as “the first among physicians and unique among philosophers,” and took daily doses of theriac — a compound antidote — that Galen prepared and oversaw. Second, his reign coincided with the Antonine Plague, a catastrophic epidemic — probably smallpox — that killed millions across the empire and shaped Galen’s clinical practice, his theorizing about disease, and his later pharmacology. Marcus’s Stoic outlook, recorded in the Meditations, has some philosophical kinship with Galen’s thought, but the evidence suggests their relationship was medical rather than philosophical.
The Emperor and His Physician
Galen’s path to imperial service passed through the gladiatorial arena. He served as physician to the gladiators in Pergamum for four years, an appointment that gave him unrivaled exposure to traumatic wounds and allowed him to develop new surgical techniques; this reputation preceded him to Rome and underpinned his subsequent appointment as physician to Commodus. (Stapley, 2024) Galen first arrived in Rome in 162 CE and quickly entered the highest aristocratic circles.(Mattern, 2008) He avoided going on Marcus Aurelius’s German campaigns by claiming that the god Asclepius had forbidden it in a dream, allowing him to remain in Italy to treat the young Commodus.(Mattern, 2013)[galen-therm91-ch06-006] Between 169 and 176 CE, while Marcus was on campaign, Galen was extraordinarily productive as a writer, completing major works including On the Usefulness of the Parts, On Anatomical Procedures, sixteen books on pulses, and the first six books of On the Method of Healing.(Mattern, 2013)
Marcus Aurelius rewarded Galen’s service in memorable terms. After Galen correctly diagnosed the emperor’s abdominal complaint as indigestion rather than fever — prescribing warm nard ointment and peppered wine — Marcus praised him three times, calling out to his chamberlain Peitholaus: “We have one physician only, and he is entirely noble.”(Mattern, 2013) Hankinson records a slightly fuller version of the praise: “he was always speaking of me as the first among physicians and unique among philosophers.”(R.J. Hankinson (ed.), 2008) Mattern reads these imperial words as doing real rhetorical work. In her analysis of Galen’s On Prognosis, the emperor functions as the ultimate judge in an agonistic narrative: his praise conclusively places Galen above all rivals in a culture where competitive medical performance before elite spectators was how reputations were made and unmade.(Mattern, 2008)
Galen also considered his connection to Marcus his highest personal accomplishment.(Mattern, 2013) Mattern records that Galen later told the emperor he had declared himself Asclepius’s servant ever since the god healed his chronic illness — a claim that linked his divine vocation directly to his imperial service.(Mattern, 2013) That this Greek physician from Pergamum, who probably never learned Latin and cited no Latin authors, could hold this honor reflects the empire’s bilingual elite culture: Marcus himself, though nominally Roman emperor, wrote his Meditations in Greek.(Mattern, 2013)
Theriac
One concrete and documented aspect of Galen’s service to Marcus was the preparation of theriac. Marcus suffered from chronic abdominal and chest pain and took theriac — a compound antidote of sixty-four ingredients including opium — every day.(Mattern, 2013) His physician Demetrius initially removed the opium from the preparation because Marcus was falling asleep during business; the result was insomnia, so the opium was restored.(Mattern, 2013) Mattern notes this constitutes evidence of physiological dependence. The emperor’s daily habit turned theriac fashionable among Rome’s wealthy: Nutton records that Marcus used a small dose as a tonic, and the imperial example transformed an expensive courtly remedy into a symbol of educated health practice.(Nutton, 2023) Mattern adds that theriac’s fashion among the rich in Marcus’s reign was explicitly driven by emulation of the emperor’s habit.(Mattern, 2013)
The Antonine Plague
Marcus’s co-emperor Lucius Verus returned from the Parthian war in 166 CE carrying plague with his army.(Mattern, 2013) The disease swept the empire over the following years. Lucius himself died of it in early 169, leaving Marcus sole emperor for the German wars.(Mattern, 2013) The epidemic that struck them both is now called the Antonine Plague. Mattern’s account of Galen’s career places the pandemic at the center of his professional life: the plague reached Italy with the returning Parthian army, Galen fled Rome for Pergamum but was recalled in 168 to join the imperial assembly at Aquileia, where Lucius died and Galen spent his most productive writing years.(Mattern, 2008) Modern scholars have most often identified the disease as smallpox, and Mattern estimates it may have killed as much as thirty percent of Rome’s population on its initial arrival in the city.(Mattern, 2008)
Galen received an imperial summons in late 168 CE and traveled to Aquileia, where he encountered the plague at full force.(Mattern, 2013) His account of what he found there is stark: “the plague descended as never before; so that the emperors immediately fled to Rome with a few soldiers, while most of us struggled for a long time to stay alive.”(Mattern, 2013) He personally lost almost all of his household slaves and his close friend Teuthras to the disease.(Mattern, 2013)
Galen treated hundreds of victims and recorded his observations in several works. His description of the characteristic rash — black, ulcerated, erupting densely over the body, forming scabs, accompanied by black diarrhea — fits what Mattern identifies as the late-forming variety of hemorrhagic smallpox.(Mattern, 2013) Modern scholars have most often identified the Antonine Plague as smallpox, possibly the first epidemic of that disease in the Mediterranean region, though no diagnosis from ancient descriptions can be certain.(Mattern, 2013) Mattern and Mattern-Parkes estimate that approximately twenty-five percent of the Roman Empire’s population may have died — perhaps fifteen million people — based on demographic gaps visible in Egyptian tax rolls and in the record of military diplomas and inscriptions.(Mattern, 2013)
Galen interpreted the disease through humoral theory. He regarded the plague as caused by excessive accumulation of black bile, and viewed the characteristic black rash and diarrhea as hopeful signs of the body expelling the noxious humor.(Mattern, 2013) His treatments included milk from Stabiae, earth from Armenia, and theriac.(Mattern, 2013) For plague transmission, he followed Hippocratic ideas: a single passage in his Praegnostic on Pulses attributes the spread to breathing corrupted air, and he invoked the tradition that Hippocrates had treated the Athenian plague of 429 BCE by purifying air with fires.(Mattern, 2013)
Mattern notes that the two external events Galen referenced most when dating his own clinical narratives were the Antonine Plague and Marcus Aurelius’s German campaign of 168.(Mattern, 2008) The plague, in other words, was not background noise but a defining event of Galen’s career — one that shaped which works he wrote, where he practiced, and which remedies he promoted.
The Missed Dissections
Galen’s decision to avoid the German campaigns had an ironic anatomical consequence. Mattern reports that army physicians who accompanied Marcus to the front were permitted to dissect slain barbarians — one of the rare Roman-period contexts where human dissection was allowed. Galen heaped scorn on his colleagues who seized this opportunity, writing that they “made little of their extraordinary opportunity because of their lack of expertise in animal dissection.”(Mattern, 2013) His own anatomy, built almost entirely on animal subjects, would later contain errors — the retiform plexus, the bicornuate uterus, the septal perforations — that would not be corrected until Vesalius in the sixteenth century.(Mattern, 2013) By staying near Rome to tend Commodus, he also stayed away from the one kind of evidence that might have corrected them.
Stoic Philosophy and the Body
Marcus Aurelius was among the most important Stoic writers of antiquity.(Mattern, 2013) He spent most of the second half of his reign fighting on the northern frontier, and it was during these campaigns that he wrote the Meditations in Greek.(Mattern, 2013)
Galen’s father ensured he studied with representatives of all four philosophical schools to cultivate non-sectarian eclecticism.(Gill_ed, 2010) As a young man, Galen attended the lectures of a Stoic teacher, a pupil of Philopator.(Gill_ed, 2010)
Yet the scholar Teun Tieleman, in Galen and the World of Knowledge (2010), argues that this shared vocabulary did not translate into personal philosophical exchange between emperor and physician. Marcus Aurelius, Tieleman concludes, seems to have had no philosophical discussions with Galen; the evidence suggests “it is very unlikely that the two men ever discussed philosophy” and that Galen’s work shows no discernible influence from his proximity to the Stoic emperor.(Gill_ed, 2010) Rebecca Flemming, in the same volume, notes that the emperor’s political virtues — providentia (foresight) — appear on imperial coinage from Trajan onward, and that this imperial ideological vocabulary may have contributed to Galen’s concept of a provident, designing nature, but frames this as a diffuse cultural influence rather than a direct intellectual exchange.(Gill_ed, 2010)
Galen also declined to publicly align himself with Stoicism. Although he borrowed Stoic physics and epistemological categories, he consistently rejected Stoic psychology — particularly the Chrysippan view that the heart is the seat of rational consciousness — as incompatible with the anatomical evidence he had gathered.(Gill_ed, 2010) The relationship between Galen’s medicine and Marcus’s Stoicism is therefore best described as one of cultural overlap and shared language rather than direct mutual influence.
See Also
- galen — Galen of Pergamum, his physician and the most important medical figure of the era
- antonine-plague — The epidemic that defined his reign
- theriac — The compound antidote Galen prepared for him daily
- stoicism — The philosophical tradition in which he wrote the Meditations
- lucius-verus — His co-emperor, who died of the plague in 169 CE
- commodus — His son, whom Galen treated during the German campaigns
- galen-on-prognosis — The treatise in which Galen records Marcus’s praise
- second-sophistic — The cultural context in which Galen’s medical performances took place