The Greatest Benefit to Mankind: A Medical History of Humanity

The last of the humours, black bile (melancholy), entered disease theory late, but in On the Nature of Man it assumed the status of an essential, if mainly harmful, humour. Visible in vomit and excreta, it was perhaps thought of as contributing to the dark hue of dried blood. Indeed, the idea of four humours may have been suggested by observation of clotted blood: the darkest part corresponded to black bile, the serum above the clot was yellow bile, the light matter at the top was phlegm. Black bile completed a coherent, symmetrical grid in binary oppositions, and the four humours – blood, yellow bile, black bile and phlegm – proved wonderfully versatile as an explanatory system. They could be correlated to the four primary qualities – hot, dry, cold and wet; to the four seasons, to the four ages of man (infancy, youth, adulthood and old age), to the four elements (air, fire, earth and water), and the four temperaments. They thus afforded a neat schema with vast explanatory potential. On the assumption, for example, that blood predominated in spring and among the young, precautions against excess could be taken, either by eliminating blood-rich foods, like red meat, or by blood-letting (phlebotomy) to purge excess. The scheme (which finds parallels in Chinese and Indian medicine) could be made to fit with observations, and afforded rationales for disease explanation and treatment within a causal framework.

The Hippocratics specialized in medicine by the bedside, prizing trust-based clinical relations:

Make frequent visits; be especially careful in your examinations, counteracting the things wherein you have been deceived at the changes. Thus you will know the case more easily, and at the same time you will also be more at your ease. For instability is characteristic of the humours, and so they may also be easily altered by nature and by chance.

… Keep a watch also on the faults of the patients, which often make them lie about the taking of things prescribed. For through not taking disagreeable drinks, purgative or other, they sometimes die. What they have done never results in a confession, but the blame is thrown upon the physician.

Their therapeutic stance was ‘expectant’: they waited and watched their patients, talking, winning trust and giving a helping hand to the ‘healing power of nature’ (vis medicatrix naturae) emphasized in the text On Ancient Medicine. Believing that ‘our natures are the physicians of our diseases’, they scorned heroic interventions and left risky procedures to others. The Oath forbade cutting, even for the stone, and other texts reserved surgery for those used to handling war wounds. That was a sensible division of labour, but surgery was also regarded as an inferior trade, the work of the hand rather than the head – a fact reflected in its name: ‘surgery’ derives from the Latin chirurgia, which comes from the Greek cheiros (hand) and ergon (work). Surgery was handiwork.

The Hippocratic doctor might disown the knife, but he prided himself on his knowledge of surgical matters – indeed the Corpus contains much now regarded as such, including a treatise On Head Injuries. Hippocratic advice proved highly influential: wounds should be kept dry, but suppuration was deemed essential to healing; the pus supposedly derived from vitiated blood which needed to be expelled from the body: pus was thus a desirable evacuation. Fractures were to be reduced and immobilized with splints and bandages. For bladder stones, catheterization was advocated, never lithotomy – such operations were left to ‘such as are craftsmen therein’; and, as a last resort in case of gangrene, amputation might be performed (vascular ligature was unknown).

Hippocratic surgical texts were thus conservative in outlook, encouraging a tradition in which doctors sought to treat complaints first through management, occasionally through drugs and finally, if need be, by surgical intervention. Hippocrates and Galen alike were dubious about surgery for cancer.

Drug therapy too was cautious. The preferred Hippocratic treatment lay in dietary regulation. Unlike sheep and goats, humans could not eat rough food; good diet was crucial to health and so, as the saying went, the first cook was the first physician. But diet meant more than food and drink – diatetica (dietetics), the cornerstone of the healing art, involved an entire lifestyle. Ancient authors linked this therapy to athletic training, and to the well-regulated life as urged by philosophers. On Regimen gave advice on taking exercise, so important to the culture of free-born Greeks, and also on sex, bathing and sleep. In winter, for instance, ‘sexual intercourse should be more frequent … and for older men more than for the younger’.

Hippocratic healing was patient-oriented, focusing on ‘dis-ease’ rather than diseases understood as ontological entities. But observation identified certain illness patterns. To the Hippocratics the paradigm acute disease was fever, and its model seems to have been malaria, the seasonal onset and regular course of which allowed it to be documented and explained in terms of humours and times of the year. Though ignorant of the role played by mosquitoes, Hippocratic physicians had a shrewd grasp of the connexions between fever and weather, season and locality. Airs, Waters, Places observed that if the rains occurred normally in autumn and winter, the year would be healthy, but if they were delayed until spring, many fever cases would occur during the summer, ‘for whenever the great heat comes on suddenly while the earth is soaked by reason of the spring rains … the fevers that attack are of the acutest type.’

Hippocratic physicians posited a broad correlation between humours and times of the year. In each season, one humour was thought to predominate. Bodily phlegm increased during the winter because, being cold and wet, it was akin to the chilly and rainy weather of a Mediterranean winter; colds, bronchitis and pneumonia were then more prevalent. When spring came, blood increased in quantity, and diseases would follow from a plethora of blood, including spring fever outbreaks (primarily benign tertian malaria), dysentery and nose-bleeds. By summer, the weather was hotter and drier, yellow bile (hot and dry) increased, and so the diseases resulting from yellow bile would multiply, that is severe fevers (falciparum malaria). With the cooler weather at the end of summer, fevers waned, but many would display the consequences of repeated fever attacks, their skins showing a dirty yellowish tinge and their spleens enlarged. The autumnal decline of fevers indicated to the Hippocratic physician that yellow bile had diminished while black bile was increasing. Seemingly the most problematic humour, black bile makes good sense in the light of awareness of the effects of malarial fevers. Philiscus, whose evidently malarial condition was described in Epidemics I, suffered from black urine and his ‘spleen stuck out’; the spleen was considered the seat of black bile. Faced with fevers, Hippocratic doctors predictably did not attempt anything heroic. Valuing regimen and diet, they gave barley water, hydromel (honey and water) or oxymel (honey and vinegar) – a ‘low’ diet with adequate fluids.

The doctor should therefore observe sickness, attending the patient and identifying symptom clusters and their rhythms. Airs, Waters, Places took it as axiomatic that understanding of locales would enable the healer on arrival in a faraway town to grasp the local diseases, so that he could ‘achieve the greatest triumphs in the practice of his art’, something important in a competitive market.

The art of diagnosis involved creating a profile of the patient’s way of life, habitation, work and dietary habits. This was achieved partly by asking questions, and partly by the use of trained senses:

When you examine the patient, inquire into all particulars; first how the head is … then examine if the hypochondrium and sides be free of pain, for … if there be pain in the side, and along with the pain either cough, tormina or bellyache, the bowels should be opened with clysters … The Physician should ascertain whether the patient be apt to faint when he is raised up, and whether his breathing is free.

Hippocratics prided themselves on their clinical acuity, being quick to pick up telltale symptoms, as with the facies hippocratica, the facial look of the dying: ‘a protrusive nose, hollow eyes, sunken temples, cold ears that are drawn in with the lobes turned outward, the forehead’s skin rough and tense like parchment, and the whole face greenish or black or blue-grey or leaden’. Experience was condensed into aphorisms; for instance, ‘when sleep puts an end to delirium, it is a good sign.’

Hippocratic doctors cultivated diagnostic skills, but the technique they really prized was prognosis – a secular version of the prognostications of earlier medicine:

It appears to me a most excellent thing for the physician to cultivate Prognosis; for by foreseeing and foretelling, in the presence of the sick, the present, the past, and the future, and explaining the omissions which patients have been guilty of, he will be the more readily believed to be acquainted with the circumstances of the sick; so that men will have confidence to intrust themselves to such a physician.

This skill had a social function: prognostic flair created a favourable impression, setting the gifted healer above quacks and diviners. To be able to tell a patient’s medical history and prospects displayed acuity. And by declaring, if need be, that death was impending, a healer escaped blame for apparent failure.

Hippocratics made no pretence to miracle cures, but they did undertake that they would first and foremost do no harm (primum non nocere) and presented themselves as the friends of the sick. This philanthropic disposition attested the physician’s love of his art – above fame and fortune – and reassured anxious patients and their relatives. Such concerns are addressed in the Hippocratic Oath (see box, opposite).

For all its later prominence, little is known about the Oath’s origins, except that it dates from between the fifth and third centuries BC. It certainly did not set general standards of conduct, for the sanctity it accords to human life is anomalous to classical moral thought and practice, abortion and infanticide being familiar practices, condoned by Plato and Aristotle. The fact that it prohibits prescribing a ‘destructive pessary’ suggests a Pythagorean influence, with their belief in the transmigration of souls.

The Oath foreshadowed the western paradigm of a profession (one who professes an oath) as a morally self-regulating discipline among those sharing craft knowledge and committed to serving others. But it was equally an agreement between apprentice and teacher. As it makes clear, Hippocratic medicine was a male monopoly, although male physicians might cooperate with midwives and nurses.

Hippocratic medicine had its weaknesses – it knew little of the inner workings of the body – but its striking innovation lay in perceiving sickness as a disturbance in the health of the individual, who would then be accorded devoted personal attention. ‘Life is short, the art long, opportunity fleeting, experience fallacious, judgment difficult,’ proclaims the first of the Hippocratic aphorisms, outlining the arduous but honourable labour of the physician.

The significance of Hippocratic medicine was twofold: it carved out a lofty role for the selfless physician which would serve as a lasting model for professional identity and conduct, and it taught that understanding of sickness required understanding of nature.

MEDICINE AND PHILOSOPHY

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.

ALEXANDRIAN MEDICINE

Aristotle’s royal pupil, Alexander, routed all his rivals, lamented there were no more worlds to conquer, and expired in 323 BC, supposedly exclaiming, ‘I die by the help of too many physicians.’ His destruction of the Persian Emperor Darius III had brought Egypt within the hellenistic sphere of influence, and after Alexander’s death science gained a prominent place at the court of King Ptolemy, who ruled from 323 to 282 BC and established his capital at Alexandria, at the mouth of the Nile.

King Ptolemy’s main cultural creations, the Alexandrian Library and the Museum (sanctuary of the Muses) installed Greek learning in a new Egyptian environment: Archimedes, Euclid and the astronomer Ptolemy were later to teach there. The library became a wonder of the scholarly world, eventually containing, it was said, 700,000 manuscripts, and its facilities included an observatory, zoological gardens, lecture halls and rooms for research.

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Thanks to Alexander’s conquests, the hellenistic world stretched from the Persian Gulf to Sicily, with Greek becoming the lingua franca of the elite. One consequence was a remarkable increase of new information on animals, plants, minerals and drugs. Alexandria also attracted medical talent, notably Herophilus of Chalcedon (c. 330–260 BC and his contemporary, Erasistratus of Ceos (c. 330–255 BC). Their writings having been lost, we know about them only through later physicians. Cornelius Celsus (fl). AD 60 reported that they dissected, or at least experimented upon, living humans, which is not inconceivable, for Greeks may have used their privileged status in Alexandria to experiment on their inferiors, especially condemned criminals.

Herophilus was apparently a student of Praxagoras of Cos (fl. 340 BC), who had improved Aristotelian anatomy by distinguishing arteries from veins. Praxagoras saw the arteries as air tubes, similar to the trachea and bronchi, conducting the breath of life (pneuma) from the lungs to the left side of the heart and thence through the aorta and other arteries to the whole body. The arteries stemmed from the heart; the veins, by contrast, Praxagoras believed, arose from the liver, their function being to carry the blood, created from digested food, to the rest of the body. The combining of blood and pneuma generated innate heat.

Herophilus practised medicine in Alexandria under the first two Ptolemies, apparently dissecting human cadavers in public. He wrote at least eleven treatises. Three were on anatomy: it was he who discovered and named the prostate and the duodenum (from the Greek for twelve fingers, the length of gut he found). He also wrote on the pulse as a diagnostic guide, on therapeutics, ophthalmology, dietetics and midwifery, and a polemic ‘Against Common Notions’.

Continuing Praxagoras’ differentiation between veins and arteries, Herophilus pointed out that the coats of the arteries were much thicker than those of the veins. Unlike Praxagoras, however, he held that the arteries were filled not with air but with blood. His most striking dissection feat was the delineation of the nerves. Demonstrating their source in the brain enabled him to conclude that they played the part preceding thinkers had ascribed to the arteries: transmitting motor impulses from the soul (intelligence centre) to the extremities. Rebutting Aristotle, he thus established the importance of the brain, distinguishing the cerebrum from the cerebellum and displaying the nerve paths from the brain and spinal cord. His description of the rete mirabile, the network of arteries at the base of the brain, shows he dissected animals as well as human corpses, since it does not exist in humans.

Herophilus also devoted attention to the liver and to ‘veins’ ending in glandular bodies which, he believed, nourished the intestines but did not pass to the liver. These ‘veins’ must have been the lacteals or chyle-vessels, whose function was explained by Aselli some two thousand years later. Praxagoras’ interest in the pulse was taken up by Herophilus. Identifying pulsation as derived from the heart, he developed a speculative classification of different classes of pulse, on the basis of magnitude, strength, rate and rhythm, and is reputed to have tried to calculate pulse by means of a portable water clock.

Erasistratus is far more nebulous and controversial. He supposedly studied medicine in Athens before settling in Alexandria, where he experimented on living animals and perhaps humans. His main discoveries concerned the brain which, like Herophilus but unlike Aristotle, he regarded as the seat of intelligence. He too distinguished the cerebrum from the cerebellum, described the cerebral ventricles within the brain, and distinguished between motor and sensory nerves. Nerves were hollow tubes containing pneuma (‘spirit’ or air), which transmitted sensation, enabling muscles to produce motion.