Five Quarts: A Personal and Natural History of Blood Read Online Free Page B

for so long? Why did he, and not others, endure? Part of it was luck, to be sure, plus sheer volume. While half of Galen’s original works were lost, his surviving literary output—some 2.5 million words, according to one count—overwhelmed his competition. But most of all, Galen’s influence rested on his blazing self-confidence. As medical historians have observed, Hippocrates, by contrast, acknowledged the potential for error in his work, areas he did not yet fully understand. But not a whit of doubt appeared under Galen’s name.
    At times I find his arrogance galling (a condition that Galen’s fifteenth-century followers would’ve diagnosed as an enflamed and leaky gallbladder, the repository of this particular emotion). But as a writer, I can’t help being impressed by the faith he inspired in others through the force of language. It’s all the more amazing to me because Galen was so often dead wrong.

    The circulatory system as conceived by Galen
    Truth be told, I find scientific blunders as fascinating as the great discoveries. It’s the main reason I enjoy reading archaic medical texts, a trusty form of time travel I undertake at libraries. Being in the position of knowing more than Galen did is satisfying, I will not deny. It’s also sobering. Two decades from now I’m sure I’ll look back and shake my head, amazed at the things Steve and I once did in the name of cutting-edge science. But there’s something else. Looking back at Galen looking forward, I am touched by his efforts to treat deadly illnesses, to alleviate suffering, however futile. Finally, he is most impressive not in having come up with so many answers but in taking on so many big questions, such as, What is the essence of life? What makes us human? Galen believed the ingredients were in the bloodstream, where a trio of incorporeal “spirits” flowed. (By contrast to the groupings of four used at that time to describe the inner and outer workings of the universe—the humors, the qualities, the elements—the spirits came in threes, reflecting the tripartite division of the soul theorized by Plato.) The first two ran in the dark, purplish blood of the veins: Natural Spirits, brewed in the liver, providing the body’s mass; and Animal Spirits, fired in the brain, producing movement. Completing the trinity were Vital Spirits, the essence that separated human beings from animals. In its fleet passage through the heart, the scarlet arterial blood was imbued with this zest, which disseminated warmth and verve throughout the body. In Galen’s reckoning, the spirits did not intermingle; the veins and arteries were separate streams.
    As scientific bunglings go, Galen was in good company. No less a genius than Leonardo da Vinci (1452–1519) made some spectacular ones in his notebooks of anatomical drawings. Leonardo, who dissected cadavers and sketched directly from them, set out with the express goal of being faithful only to the evidence of his eyes. Unlike Galen, he held a lifelong aversion to verbiage and believed that drawing was the only uncontestable means of expression. That being said, Leonardo still could not escape Galen’s lingering influence. This groundbreaking artist who rendered with astonishing accuracy the chambers of the heart, for example, and the fetus in utero, nevertheless added fictitious plumbing to the human body—canals, ducts, and veins—to accommodate humoral theory. Likewise, he drew the spleen cartoonishly large, proportional to its inflated role in secreting the illusory black bile. Another fallacy perpetuated by Galen and then by Leonardo was the kiveris vein, which resolved the biological puzzle of why pregnant women stopped menstruating. The answer: Menstrual blood was converted into mother’s milk, of course, and this “milk vein” conveyed it from the uterus to the breasts. Uniquely male anatomy was fictionalized, too. In cross sections of the penis, Leonardo added a phantom vein for “vital