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Claudius GALEN was born at Pergamum, in Asia Minor, A.D. 131. He received a careful training in the philosophy of Aristotle and Plato, and in medical practice. At his father's death he studied for many years at Alexandria, where he gained great reputation as an anatomist. At the age of 34 he established himself as a physician in Rome. But the great superiority of his scientific knowledge brought on him the jealousy of the Roman physicians, and he was ultimately driven from the city. The place and the precise date of his death are uncertain, but allusions in his writings show that he must have lived at least till the end of the second century A.D.
Galen represents the final outcome of the biological research of antiquity, instituted by Aristotle, and carried on at Alexandria with extraordinary zeal and success under the first two Ptolemies. In after times, when the great university had abandoned itself to metaphysical discussion, the systematic study of medicine, like geometry, had failed to attract thinkers and observers of original power, and had been carried on somewhat languidly. Galen revived it and enriched it with independent researches of the greatest value, to which, during the twelve centuries that followed, little addition was made.
A space of five hundred years separates Aristotle from Galen. The principle results achieved in that period may be briefly indicated, thought it is not always possible to determine what is due to Galen from what he owed to others. Aristotle, who discovered many of the fundamental principles of life, and who described many of its forms and organs with astonishing accuracy, was yet in almost complete ignorance of the tissues on which the two fundamental facts of animal life--motion and sensation--were dependent. Of the contractility of muscle, of the conductivity of nerve, of the brain as a centre of force, he knew nothing. Flesh or muscle, to him, was simply a complex of small blood-vessels, useful mainly as a covering to retain animal heat. Nerves for him were mere tendons; and the brain was a reservoir of cold substance the function of which was to control the temperature of the heart. (Ogle's translation of Aristotle's de Partibus, pp. 172-7).
In Galen all these errors are corrected in a manner with which the modern physiologist could find but little fault. He describes the property of muscular tissue and the function of the principal muscles with perfect clearness. Of nerve he remarks that it is now admitted by all physicians that without it there can be neither motion nor sensation. He explains that section of a nerve is followed by paralysis and by loss of feeling in the part to which it is distributed. But he was aware, also, that the nerves originated nothing; they were simply channels through which sensation and motion were communicated from the brain and spinal cord to the muscles and other organs of the body. The brain he calls in some places an Arché, in others the centre of psychical force; the spinal cord was of the same nature. He describes with a near approach to accuracy the nerves issuing from the brain and from the cord; and he states that if the cord be cut through or injured in any part all the parts supplied with nerves coming from below the point of section or injury are deprived of motion and of feeling. From all this it is apparent that the biological conditions of animal motion were clearly grasped by Galen. What was wanting to him was the knowledge of mechanical principles not attained till the seventeenth century. Galen put this question (Treatise on Spasm): the limbs of animals weigh, and like other heavy bodies tend to fall to earth; how is it that they can move in every direction? Some force, he replied, came to the muscles from the brain through the nerve, and acted "as a vehicle or wing of motion." Beyond this it was impossible to go, until Galileo, Newton, and others had founded the science of Rational Mechanic, and the equality of Action and Reaction has been understood. Till then the void must be supplied by such metaphysical abstractions as vital force or animal spirits.
As to the blood and blood-vessels, Galen's views were of course imperfect, yet they show an advance on previous knowledge. The anatomical distinction between arteries and veins was known to him. He describes the blood of the arteries as light and thin and modified by the air breathed into the lungs: the blood of the veins being dark and thick. He refutes in great detail the view of Erasistratus that the arteries contained air, and that when an artery was wounded, air escaped in the first place: the blood that followed being absorbed from the venous system. It has been lately shown that Aristotle came nearer the truth in this matter than his immediate successors.
Into Galen's descriptions of the other organs of the body it is not possible here to enter. His scientific works, summing up the labours of the Alexandrian Schools with important additions of his own, represent Anatomy and Physiology as known to the ancient world. For more than a thousand years no addition was made. At the Renaissance, the anatomists of Italy brought their intellect to bear on this rich inheritance of knowledge. They altered much; but still greater was the part which they had no need to alter.
Of Galen as a physician little need be said here. It is probable that the anatomical researches of Alexandria, which did much for Surgery, had not been of equal benefit to Medicine: perhaps, indeed, had injured medical practice by diverting attention from the whole to the parts. A mass of remedial agents, most of them futile, had not added to the dignity or efficacy of the art. Galen's principal service in this matter was to revert to the direct and simple ovservations of Hippocrates, whose transcendent greatness he recognized, and of whom he speaks with unvarying respect as the "servant of Nature." They physician, he said, should be a philosopher in the twofold sense of that word. He should have studied the order of the universe as mathematical science has revealed it: and he should be a master of his own passions, preferring always the pursuit of truth to professional gain.
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| This biography is
reprinted from The New Calendar of Great Men. Ed. Frederic
Harrison. London: Macmillan and Co., 1920. |
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