Читать книгу The Greatest Benefit to Mankind: A Medical History of Humanity - Roy Porter - Страница 23

With Greek philosophers praising health as one of the greatest blessings of life, medicine became implicated in wider debates about human nature and the status of the body. The earliest writer to mention Hippocrates and his theories, Plato (427–437 BC) developed a series of analogies to divide human nature into three functions – reason, spirit, and appetites – located respectively within the brain, the heart and the liver, and all potentially in conflict. Only in the philosopher would reason, aided by spirit, triumph over sordid desires. The Republic’s distinctions between reason and appetite, mind and body, was of utmost philosophical and psychological significance. Plato’s place in later medical thinking, however, rests on the Timaeus (c. 375 BC). This pictured the body as built up from transcendental geometrical shapes. The human frame was constructed by the Creator with specific purposes in mind; hence medicine had a discernible teleology. Somatic in orientation, the Timaeus taught that morality was not simply a matter of education; behaviour might also be determined by organic constituents, by excesses or deficiencies in the spinal marrow which affected the sensations of pleasure and pain; madness might thus have a physiological cause, to be treated by medical means. Because the mind was influenced by the body, the doctor had a part to play in teaching virtue. Advancing a physiology compatible with Hippocratic medicine, the Timaeus became a highly influential text, linking medicine and philosophy, health and politics.

THE OATH

I swear by Apollo the healer, by Aesculapius, by Health and all the powers of healing, and call to witness all the gods and goddesses that I may keep this Oath and Promise to the best of my ability and judgment.

I will pay the same respect to my master in the Science as to my parents and share my life with him and pay all my debts to him. I will regard his sons as my brothers and teach them the Science, if they desire to learn it, without fee or contract. I will hand on precepts, lectures and all other learning to my sons, to those of my master and to those pupils duly apprenticed and sworn, and to none other.

I will use my power to help the sick to the best of my ability and judgment; I will abstain from harming or wronging any man by it.

I will not give a fatal draught to anyone if I am asked, nor will I suggest any such thing. Neither will I give a woman means to procure an abortion.

I will be chaste and religious in my life and in my practice.

I will not cut, even for the stone, but I will leave such procedures to the practitioners of that craft.

Whenever I go into a house, I will go to help the sick and never with the intention of doing harm or injury. I will not abuse my position to indulge in sexual contacts with the bodies of women or of men, whether they be freemen or slaves.

Whatever I see or hear, professionally or privately, which ought not to be divulged, I will keep secret and tell no one.

If, therefore, I observe this Oath and do not violate it, may I prosper both in my life and in my profession, earning good repute among all men for all time. If I transgress and forswear this Oath, may my lot be otherwise.

‘The soul and body being two, they have two arts corresponding to them,’ Plato stated, making similar links in the Gorgias: ‘there is the art of politics attending on the soul; and another art attending on the body, of which I know no single name, but which may be described as having two divisions, one of them gymnastic, and the other medicine.’ Thanks to Plato, western thinking could consider medicine as having its share in understanding human nature. Greek thinking thus emphasized the common ground between what would later become the separate disciplines of philosophy, medicine and ethics. Health depended upon temperance and wisdom, or proper self-control. Achieved through moderation in eating, drinking, sex and exercise, bodily health became the template for healthy thinking (sōphrosynē, soundness of mind). To later Stoic philosophers likewise, the wisdom of the sage required the attainment of true health; for their part Epicureans stressed the supreme desirability of freedom from pain.

Plato’s pupil Aristotle also put forward hugely influential views on the constitution of life. A doctor’s son from Stagira in Thrace, Aristotle (384–322 BC) went to Athens to study with Plato, later becoming tutor to Alexander the Great (356–323 BC). His towering role in theorizing about metaphysics and cosmology, ethics, politics, poetics and thinking itself involved many achievements: the creation of a scientific method; the pursuit of teleological ways of thinking; and the impetus he gave to biological research. Questioning Plato’s transcendental ideas, Aristotle called for the systematic observation of nature. Whereas Plato distrusted sense experience, his pupil launched a programme of empirical investigation into the natural world – into zoology, botany and meteorology. Nature did nothing in vain, so body parts had to be explained in respect of their purpose (teleology). Aristotle discussed such final causes in terms of a wider fourfold theory of causation. For nearly two thousand years, Aristotelian methodology provided the framework for scientific investigation.

Later hailed by Dante as the ‘master of the men who know’, Aristotle was the first who systematically used dissection findings (animal not human) as a grounding for his biomedical theories. What he recorded occasionally puzzled his successors. In his description of the heart, he refers to ‘three chambers’ connected to the lung; later investigators were baffled which animals he was referring to. While revealing the veins as a connected system of vessels extending from the heart throughout the whole body, he did not distinguish between veins and arteries, applying the same term to both.

Observing the embryo developing within eggs, Aristotle perceived the beating heart as the first sign of life, concluding that it must be the prime mover of life and coeval with the whole body. The blood contained within the heart and blood vessels became correspondingly decisive. Blood was the nutrient the vessels absorbed from the intestines: ‘this explains why the blood diminishes in quantity when no food is taken, and increases when much is consumed.’

The idea of a nervous system paralleling the veins and arteries was as yet unformulated, so it is not surprising that Aristotle did not locate the seat of the soul, the source of movement and sensation, within the brain, but in the heart, stressing its physiological primacy within the human body. It was also the source of innate heat; pulsation was the result of a sort of boiling movement (ebullition) in the blood, causing it to press against the heart walls and pour out into the blood vessels. The heart’s heat dilated the lungs, fresh air rushed in, cooled the blood, and, warmed by the blood’s heat, was then expired. The brain had a part to play in these vital processes. Being naturally cold, it served as a refrigerator, helping to cool the blood’s innate heat. It also brought on sleep. Its function was that of a regulator, adjusting the organism as a whole.

The discussions of psychology in Aristotle’s On the Soul, On Sleep and Waking, On Sensation and On Memory long intrigued doctors and philosophers alike; and two thousand years later his teleological doctrines shaped the physiology of William Harvey (See Chapter Nine). In the shorter term his anatomy was taken up and revised by the next generation, particularly by Diocles of Carystos (fl. 320 BC), and two doctors working in Alexandria, Herophilus and his contemporary Erasistratus.