GALEN’S LEGACY

The Texts through Time


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The volume of Galen’s literary output is astonishing: scholars calculate that 10 percent of all extant ancient Greek literature was written by Galen. The range of his writing is as diverse as his curiosity. He wrote for other physicians—treatises, case studies, polemical arguments, and more—but he also produced texts for a more general readership. And he wrote many that went beyond narrowly medical topics, including a large number on philosophy, as well as textual commentary and linguistic studies of Greek comedy.

A delicately colored illustration of two seated men in conversation. The man on the left holds a book, while the one on the right holds a scroll. A line of text seems to issue from the mouth of the bearded figure on the right.

Galen, in discussion with Hippocrates, presents a scroll that reads: “I mean to eat to live, while others live to eat.” Detail from Manfredus de Monte Imperiali, Liber de herbis et plantis (Italy, first half of the 14th century), fol. 1v. Bibliothèque nationale de France, Département des Manuscrits: Latin 6823. Photo: gallica.bnf.fr / Bibliothèque nationale de France.

Despite the destruction of his personal library in the fire of 192 CE, a substantial amount of Galen’s work has come down through time—even some texts that the physician considered to have been permanently lost. He was preoccupied with his legacy from early in his career and arranged for his writings to be copied, distributed to friends, or deposited in libraries, and this did indeed help ensure their endurance. But even beyond mere preservation, Galen was concerned that his writings be properly understood, so he penned guidance on how to approach his vast oeuvre—writing books on how to read his own books, such as The Order of My Own Books and the final chapter of the Art of Medicine. He also wrote summaries and abridgments of his longer works, thus creating texts that were more affordable and easier to understand for readers with less background in the subjects. Further, Galen worried that treatises might be forged under his name. His fear of literary imposters was not unfounded: after overhearing an argument about whether a book attributed to Galen was authentically his, the physician wrote My Own Books, a comprehensive annotated bibliography of his output. Yet inauthentic texts nonetheless entered circulation under his name, and the disentanglement of treatises published under Galen’s “label” from those that were genuinely written by him continues to this day. Historians note that the very existence of such texts witnesses the power of his influence—imitation, as the saying goes, is a form of flattery.

After the fall of the Western Roman Empire, interest in Galen’s writings faded along with the works of other Greek authors in this Latin-speaking region. But in Byzantium—the Greek-speaking part of the Eastern Roman Empire—Galen’s texts continued to be studied, edited, and translated. In Alexandria (in present-day Egypt) during the sixth century, a selection of Galen’s works was assembled into a new corpus known as “The Sixteen Books” as a solution to the challenge presented by the voluminousness of Galen’s output. Despite the “sixteen” in its name, the corpus actually included twenty-four treatises or extracts from longer works, and the collection was read in a specific order and accompanied by lectures and commentaries. Although far from comprehensive, this reading list was substantial and offered a well-rounded but succinct presentation of Galen’s medical writings. It was such a useful framework—including texts on anatomy, physiology, pathology, therapeutics, hygiene, and dietetics—that this curriculum became the core of medical education well beyond Alexandria and guided readers for centuries. 

The path of Galen’s texts into our present era has not always been the straightforward journey that the physician himself imagined. In addition to being edited and compiled, his writings frequently arrived through translation from Syriac, Arabic, Hebrew, Latin—and sometimes through more than one of these languages—rather than directly from his original Greek.

An illustration featuring a row of four bearded figures, seemingly haloed and vividly attired in yellow, green, and brown. Each figure stands within an arch in a colonnade. Around them are smaller figures, Arabic text, and decorative motifs.

Galen in the company of three sages. From left to right: Hayqār Hakīm, Plato, Galen, Aristotle. From the frontispiece of Abū Alī Yahyā Ibn 'Isā Ibn Jazla, The arrangement of bodies for treatment (Taqwīm al-abdān fī tadbīr al-insān; late 17th century). Library of the University of Glasgow, Scotland: GB 247 MS Hunter 40 (T.1.8). Photo: Library of the University of Glasgow, Scotland.

The so-called Sixteen Books were translated into Syriac (an Aramaic language used by Christians in the Near East) by 550 CE and into Arabic by the tenth century, in turn becoming the basis for medical education in the Islamic world (which also included populations of Christians and Jews).

Two facing pages in a book. Both pages have lines of Arabic text in black, with some writing in red.

Galen, Treatise on Bones for Beginners (Maqala fi al-ʿizam li-lmutaʿalimin), trans. Hunayn ibn Ishaq (809–873 CE), fols. 62v, 63r. US National Library of Medicine: MS P 26. Photo: US National Library of Medicine.

A letter written by a Christian physician in Baghdad (present-day Iraq) in the middle of the ninth century describes this translation activity: Hunayn ibn Ishaq (d. 873) lists 129 works by Galen that had been translated into Syriac and Arabic, often by himself or by members of his circle. But the letter was not just a bibliography: Hunayn also provided an outline of his approach to the task of translating Galen, the names of people who sponsored the project, and the challenges he encountered in his search for Greek manuscripts. These translations from the late-antique Byzantine and Arabic worlds have been tremendously important in the transmission of the Galenic corpus, and many of these Arabic texts survive in some form today, even in cases in which the original Greek has been lost. But, beyond transmission, thinkers in the Islamic world continued to work in a Galenic tradition and extended his style of medical inquiry: writers such as Ibn Sina (Avicenna; 980–1037) and Ibn al-Nafis (1213–1288)—to name only two of many—organized, developed, challenged, and added to Galenic doctrine, thus advancing medicine in the same spirit as Galen.

A page with black-and-red text and lavish gilding. At the top is a pentagonal illustration in gold and pale blue, with small red and purple circles scattered throughout.

Opening of the fourth book from Avicenna (Ibn Sina), The Canon of Medicine (Al-qanun fi al-tibb; Iran, early 15th century), fols. 386v, 387r. US National Library of Medicine, National Institutes of Health: MS A 53. Photo: Bruce M. White / Institute for the Study of the Ancient World.

A page with lines of text and two grids, each composed of red-bordered squares.

Diagram for a diagnosis by pulse. From Ibn al-Nafis al-Qurashi (?), The Concise Book (Kitab al-mujiz; 17th century), fols. 8v, 9r. US National Library of Medicine, National Institutes of Health: MS A 43. Photo: Bruce M. White / Institute for the Study of the Ancient World.

Beginning in the eleventh century, the writings of Galen were reintroduced in the West in the form of Latin translations from these Arabic versions. And, by the middle of the thirteenth century, Latin translations—now from both Arabic and Greek—influenced the study of medicine in universities, particularly in Montpellier (in present-day France), as well as certain centers in Italy and Spain. During the Renaissance, as the population of people able to read Greek expanded and as thinkers looked back to antiquity with renewed interest, there were major developments in the study of Galen. Political events also added to the accessibility of Greek works: after the fall of the Byzantine Empire in 1453, there was an influx of both Greek thinkers and manuscripts into Western Europe. By the fifteenth century, scholars were able to compare the translations of Galen in circulation with the original Greek texts, and their findings—mistranslations, copying errors, and wrong identifications—led to a flurry of work on the Galenic corpus as a whole. 

An early printing house in Venice, the Aldine Press, famous for its Greek and Latin publications (as well as for the invention of italic fonts), produced the first printed edition of Galen’s complete works in Greek in 1525.

A black-and-white photo of a title page printed in Greek and Latin. In the center is an emblem depicting a dolphin wrapped around an anchor.

Title page from the first volume of the complete works of Galen (Venice: Aldine Press, 1525), edited by Joannes Baptista Opizo and Andreas Asulanus. Wellcome Collection: 2507/D/1 Vol. 1. Photo: Wellcome Collection. CC BY 4.0.

Although a few Galenic treatises had been printed earlier by competing publishers, none of these printings had as great an impact on Galen’s reception as this Aldine edition. Many of the texts it contained became widely available to the medical public for the first time in over a thousand years, leading to renewed appreciation for the meticulousness of his work and to rediscovery of various facets of his thinking. Indeed, Galen arguably reached the very height of his popularity in the mid-sixteenth century. His major work on anatomy—unknown in the West for hundreds of years—spurred a new wave of scientific research, which ironically led to the dethroning of his anatomical authority. Yet even as faith in various aspects of Galen’s medical theories began to wane, his texts only gradually lost their central position in medical education. Oxford University continued to offer lectures based on Galenic texts into the eighteenth century, and Karl Gottlob Kühn’s nineteenth-century publication of the complete works, which remains the standard scholarly edition for many of the texts, was produced by a physician for an audience of physicians who continued to comb Galen’s writings for medical wisdom. It is only in the past century and a half that medicine has completely divorced itself from his long-lived influence.