Galen of Pergamum (ca. 130-ca. 200)

Of all the authors of antiquity, however, none possesses so just a claim to the title of anatomist as Claudius Galenus, the celebrated physician of Pergamum, who was born about the 130th year of the Christian era, and lived under the reigns of Hadrian, the Antonines, Commodus and Severus. He was trained by his father Nicon (whose memory he embalms as an eminent mathematician, architect and astronomer) in all the learning of the day, and initiated particularly into the mysteries of the Aristotelian philosophy. In an order somewhat whimsical he afterwards studied philosophy successively in the schools of the Stoics, the Academics, the Peripatetics and the Epicureans.

When he was seventeen years of age, his father, he informs us, was admonished by a dream to devote his son to the study of medicine; but it was fully two years after that Galen entered on this pursuit, under the auspices of an instructor whose name he has thought proper to conceal. Shortly after he betook himself to the study of anatomy under Satyrus, a pupil of Quintus, and of medicine under Stratonicus, a Hippocratic physician, and Aeschrion, an empiric. He had scarcely attained the age of twenty when he had occasion to deplore the loss of the first and most affectionate guide of his studies; and soon after he proceeded to Smyrna to obtain the anatomical instructions of Pelops, who, though mystified by some of the errors of Hippocrates, is commemorated by his pupil as a skilful anatomist. After this he appears to have visited various cities distinguished for philosophical or medical teachers; and, finally, to have gone to Alexandria with the view of cultivating more accurately and intimately the study of anatomy under Heraclianus. Here he remained till his twenty-eighth year, when he regarded himself as possessed of all the knowledge then attainable through the medium of teachers. He now returned to Pergamum to exercise the art which he had so anxiously studied, and received, in his twenty-ninth year, an unequivocal testimony of the confidence which his fellow-citizens reposed in his skill, by being intrusted with the treatment of the wounded gladiators; and in this capacity he is said to have treated wounds with success which were fatal under former treatment. A seditious tumult appears to have caused him to form the resolution of quitting Pergamum and proceeding to Rome at the age of thirty-two. Here, however, he remained only five years; and returning once more to Pergamum, after travelling for some time, finally settled in Rome as physician to the emperor Commodus.

The anatomical writings ascribed to Galen, which are numerous, are to be viewed not merely as the result of personal research and information, but as the common depository of the anatomical knowledge of the day, and as combining all that he had learnt from the several teachers under whom he successively studied with whatever personal investigation enabled him to acquire. It is on this account not always easy to distinguish what Galen had himself ascertained by personal research from that which was known by other anatomists. This, however, though of moment to the history of Galen as an anatomist, is of little consequence to the science itself; and from the anatomical remains of this author a pretty just idea may be formed both of the progress and of the actual state of the science at that time.

Greek physician considered second only to Hippocrates of Cos in his importance to the development of medicine, Galen performed extensive dissections and vivisections on animals. Although human dissections had fallen into disrepute, he also performed and stressed to his students the importance of human dissections. He recommended that students practice dissection as often as possible. He studied the muscles, spinal cord, heart, urinary system, and proved that the arteries are full of blood. He believed that blood originated in the liver, and sloshed back and forth through the body, passing through the heart, where it was mixed with air, by pores in the septum. Galen also introduced the spirit system, consisting of natural spirit or "pneuma" (air he thought was found in the veins), vital spirit (blood mixed with air he believed to found in the arteries), and animal spirit (which he believed to be found in the nervous system). In On the Natural Facilities, Galen minutely described his experimentation on a living dog to investigate the bladder and flow of urine. It was Galen who first introduced the notion of experimentation to medicine.

Galen believed everything in nature has a purpose, and that nature uses a single object for more than one purpose whenever possible. He maintained that "the best doctor is also a philosopher," and so advocated that medical students be well-versed in philosophy, logic, physics, and ethics. Galen and his work On the Natural Faculties remained the authority on medicine until Vesalius in the sixteenth century, even though many of his views about human anatomy were false since he had performed his dissections on pigs, Barbary apes, and dogs. Galen mistakenly maintained, for instance, that humans have a five-lobed liver (which dogs do) and that the heart had only two chambers (it has four).