Galenus, Claudius. — Physician and philosopher, born at Pergamum in A.D. 129, died there in 201. He travelled to Smyrna, Corinth, Alexandria and in 162 was in Rome. He was court physician to Marcus Aurelius, for whom he cared for the young Commodus.
A follower of Hippocrates in medicine, his most original contribution to this discipline was physiological, through his studies on the functioning of the nervous system and on the brain, heart, liver, for which he made use of vivisection on animals—monkeys, goats and pigs. He adopted the doctrine of the four temperaments: phlegmatic, sanguine, choleric, melancholic, whose proper humoral balance (eucrasia) produces health, while their imbalance produces disease.
Based on the principle *Contraria contrariis* and on every medicinal treatment, Galen attributed a humoral characteristic.
His writings number about 400, of which (of the 108 that have come down to us) the most important are *Anatomical Investigations* in 15 books, *Functions of the Organs of the Human Body* in 17 books, *Teachings of Hippocrates and Plato* in 6 books, *On Natural Faculties* in 3 books; important also are *The Art of Medicine* and *Therapeutic Method*, known in the Middle Ages respectively as the *Microtechnum* and the *Macrotechnum*.
He also had philosophical concerns; he was a convinced teleologist; he saw in nature the concatenation of causes that rises up to a generative intelligence, though not entirely detached from matter: it is precisely the study of the human body that enables one to understand the excellence of the spirit that governs the world.
His approach may be defined as eclectic Aristotelianism. The influence of Aristotle is evident especially in his logic (the fourth figure of the syllogism, which Galen derived from his analysis of the modes of the first figure of Theophrastus and Eudemus, is well known), in physics and metaphysics; while in psychology (e.g., in the question of the division of the soul) he inclines toward Platonism. For him, philosophy, identified with religion, is the summit of all goods.
Galen knew of Christianity and speaks of it in two passages of the work *On the Pulse*, in connection with the tenacity with which certain physicians assert their opinions without justification, in a manner similar to those who place themselves under the school of Moses and of Christ (*De puls.*, VIII, 579 Kühn): it would indeed be easier, he adds, to change the opinions of disciples of Moses and of Christ than those of physicians and philosophers loyal to their factions (ibid., p. 657).
He praises Christians in a passage not found in Galen’s own works, but cited as his by the Arab writer Ibn al-Aṭīr, reported in turn by Abū ’l-Fidā’ (*Historia Anteislamica*, ed. Fleisch, p. 109). Noting the usefulness of parables for the comprehension of concepts and remarking on the use Christians make of them, he states that they thus behave like true philosophers. We see before our eyes their contempt for death. A kind of modesty inspires their avoidance of sexual intercourse. Among them there are men and women who have abstained from union throughout their lives. And there are others who, through the direction and discipline of the soul and rigorous application, do not yield to true philosophers.
This passage, whose authenticity there is no reason to deny, demonstrates Galen’s fair judgment regarding the new religion, which was the object of so many closed-minded and violent attacks. — See pl. CXXVI.