Osler’s Razor

Peter Medawar

  • The Youngest Science by Lewis Thomas
    Viking, 256 pp, $14.75, February 1983, ISBN 0 670 79533 X

Lewis Thomas is a physician, a scientist, a medical administrator, and a man of letters whose previous books, The Lives of a Cell (1974) and The Medusa and the Snail (1979), and occasional writing for the New England Journal of Medicine have brought him a large following. The Youngest Science will meet his fans’ highest expectations.

In American letters I can compare Thomas only with Oliver Wendell Holmes (the father of the one whom Americans think of first). But although both were medical professors and, in their time, deans, their affinity does not really go much deeper than the relaxed and genial style they share: only a young left-wing hothead, insisting always upon relevance and social engagement, would object to being compared with Holmes. As Lewis Thomas is none of these things, he will not mind it being said that his opening paragraph is very much in Holmes’s style: ‘I have always had a bad memory, as far back as I can remember. It isn’t so much that I forget things outright, I forget where I stored them. I need reminders, and when the reminders change, as most of them have changed from my childhood, there goes my memory as well.’

Lewis’s father practised medicine in an old clapboard house, the backyard of which abutted onto a cutting that gave way to the Long Island Railroad; and the dilapidated old church which his family attended ‘most Sundays’ today bears a sign saying that, so far from representing the Dutch Reformed Church, it is Korean Protestant – an apostasy which cannot but strike an Episcopalian as a non-sequitur. His mother’s family were Pecks and Brewsters, who, like everyone else in this part of Connecticut, were rated Mayflower progeny – something which his mother doubted. In the Thomas household there was never an end to worrying about money – ‘the family took it for granted that my father had to worry about his income at the end of every month’ – for few of Dr Thomas’s patients paid promptly and many not at all, though ‘some sent in small cheques, once every few months.’ Thus the domestic economy of the Thomas household could not have been farther removed from that of a great metropolitan hospital in the USA, with its elaborate security checks and something akin to a secret police to prevent patients slipping out without paying their dues. ‘The practice of medicine was accepted to be a chancy way to make a living, and nobody expected a doctor to get rich, least of all the doctors themselves ... my father’s colleagues lived from month to month on whatever cash their patients provided and did a lot of their work free, not that they wanted to or felt any conscious sense of charity, but because that was the way it was.’

These are considerations to keep in mind; and when, in countries lacking a national health service, people in need of medical attention accuse doctors of being mercenary, they would do well to remember that the profession has a substantial moral credit balance, for there is no thought or suggestion here that old Dr Thomas was alone or even unusual in his magnanimity. It was a sign of bad times in the Thomas household when his mother went foraging round the house for four-leaf clovers, murmuring: ‘The Lord will provide.’ This superstitious ritual had one purpose only: to get old Dr Thomas’s patients to pay their bills. He was not then ‘old’ – I call him so only to distinguish père from fils.

Lewis Thomas’s closest friend as a fourth-year medical student at Harvard was the Albert Coons who later became one of America’s most distinguished immunologists. It was then Coons’s lot to write the yearbook for the class of 1937. Lewis Thomas was on his editorial staff and prepared and circulated a questionnaire addressed to graduates from the years 1927, 1917 and 1907. It dealt with matters of internship and residency training; and also, delicately and with a promise of anonymity, asked the respondent for an estimate of his income for 1937. A space was left for any advice or general comments that might benefit the class of 1937. ‘The average income of the ten-year graduates was around $3,500; $7,500 for the 20-year people,’ Thomas reports. ‘One man, a urologist, reported an income of $50,000, but he was an anomaly; all the rest made, by the standards of 1937, respectable but very modest sums of money.’ The general drift of the advice given by the alumni was that medicine was the best of professions but not a good way to make money: if you could, you should marry a rich wife. In the meantime, work long hours, take very little time off, and don’t expect to be prosperous.

Like his fellow practitioners in Flushing, old Dr Thomas worked from home. His consulting-room and waiting-room were on the first floor; the dining-room was only one door away from the waiting-room, ‘so we grew up eating more quietly and quickly than most families.’ The household comprised a living-in maid on the third floor, a laundress who worked in the basement and a passionate Italian gardener; however, his mother always did the cooking, even when there was a maid, and when there wasn’t, she did all the cleaning and everything else in the house.

For those who believe that the riotous misbehaviour of young people is a modern innovation, the outcome of television, non-attendance at Sunday school and other contrivances of Satan, it is reassuring to know that ‘all the children in Flushing were juvenile delinquents, roaming the town in the evening, ringing door bells and hiding, scrawling on the sidewalks with coloured chalk and, at Halloween, breaking windows and throwing garbage cans into front yards.’ They shoplifted at Woolworth’s, twisted street signs to point in the wrong direction and at the age of ten were buying and smoking Piedmont cigarettes and breaking candy-vending machines. ‘We were expected to be bad, there was no appealing to our better selves because it was assumed that we had no better selves.’ An additional cause of grievance was that the children turned out rather well.

In watching his father, Lewis came to learn of the style of medicine that is farthest removed from the modern scientific medicine of which in later years Lewis was to be such an ardent advocate and skilful practitioner. Lewis is full of admiration for his father’s unremitting attention and kindliness towards his patients. One dramatic episode is described of the kind which all laymen and television producers take for granted as a matter of everyday occurrence in the life of a family doctor. Lewis’s father arrived at the household of an old Flushing family a few minutes after the unmarried daughter had delivered a baby which the grandmother was about to smother. His father reasoned with the family and arranged for the baby to be taken in by the Catholic nuns at the foundling hospital where the nursing was the best his mother had ever seen. There is, of course, an element of everybody’s father about old Dr Thomas, who could be heard to swear ‘not very demoniacally’ when called out of bed to attend sudden illnesses, births and deaths, or any one of a hundred other causes of being scared or in need of help. Lewis was often taken as a passenger when his father drove off on his rounds, and was fascinated by the contents of his father’s doctor’s suitcase, containing, apart from stethoscope etc, a variety of ampoules, syringes and needles. The only really indispensable drug was morphine; adrenalin was carried in case of an emergency which never in fact arose: anaphylactic shock. In due course insulin was added to the pharmacopoeia.

From the standpoint of today’s medicine a doctor of his father’s generation had very few if any specific remedies for human ills, but with the hindsight that Lewis’s sympathetic account of his father’s practice makes possible, we can easily see that alongside the good practitioner’s general medical wisdom, kindness and psychological support, the older physician had one other factor of immense importance working in his favour: his patients believed the doctor and believed that his ministrations would do them good. Indeed, they believed in medicine as well as in doctors. Nothing else in art and literature could make this point more clearly than the closing scene of Puccini’s La Bohème. Mimi is within a few hours of death from consumption. Extremities are cold, the pulse barely perceptible, the breathing light and shallow: but one of the household resolves to pawn his overcoat and another her trinkets to raise enough money to buy some ... medicine! A fat lot of good that would have done, speaks the voice of modern scientific medicine, expressing no opinion on the importance of solicitude, both for the patient and for her anxious friends. The days were yet to come of a doctor’s being quizzed by patients who had read the latest preposterously sanguine article in one or other digest magazine.

Another consideration that worked for the doctor was that patients did get better – some of them, anyway – for ‘there are very few illnesses like rabies that kill all comers.’ Most illnesses tend to kill some patients and to spare others, ‘and if you are one of the lucky ones and have also had at hand a steady, knowledgeable doctor, you become convinced that the doctor saved you.’ it is just this element of post hoc, propter hoc, I believe, that accounts for the widespread belief that psychoanalytic treatment is efficacious. Of a patient’s conviction that the doctor saved him Lewis remarks: ‘I should be careful not to believe this of myself if I became a doctor.’ The scientific physician now has a lot of fun at the expense of the voluminous and complex prescriptions of previous generations – written out in Latin ‘to heighten the mystery’. These medicines differed in taste, colour, smell and the ‘likely effects of the concentrations of alcohol used as solvent’. They had been in use so long that they had the ‘incantatory power of religious ritual’. They were prescribed because the patients expected them, not because the physician believed that they did any good except as placebos, and to give the patient something to do while the illness was working its way through its appointed course.

Fads and fashions of therapy had already begun to sweep through medicine in Lewis’s father’s time. The ‘minuscule quantities of drugs’ specified by homeopathic principles took hold as a reaction against the powerfully toxic drugs in common use, such as mercury, arsenic, bismuth, strychnine, aconite and the like. The patients survived as well as they would have done without treatment of any kind and were spared the consequences of intoxication by arsenical and mercurous compounds.

Anyone who has spent any part of their lives in boarding-schools will probably remember how their schooldays were darkened by the capital importance attached to regularity in the movement of the bowels – an attitude of mind still sometimes to be found among old-fashioned nurses and in some cottage hospitals. Lewis Thomas is especially amusing about the theory that represented the very apotheosis of bowel mystique: the theory according to which human disease is caused by the absorption of toxins from the lower intestinal tract – ‘autointoxication’. Thomas’s father was persuaded to use on his patients a round lead object about the size of a bowling ball encased in leather. The procedure for promoting peristalsis was to lie the patient flat on his bed and roll the ball clockwise around the abdomen, following the course of the colon. Old Dr Thomas was disappointed in its use and somehow the ball found its way to a neighbour’s house, in the garden of which it was rediscovered and announced in the headlines of the local newspaper as a cannon ball from the Revolutionary War, discovered ‘to the mystification of visiting historians, who were unable to figure out the trajectory from any of the known engagements of the British or American forces’. Lewis’s father, as his son would have done, claimed that he had in a sense made medical history. He was never again caught up in any medical fad. He remained a sceptic about psychosomatic disease. He indulged Lewis’s mother by endorsing her administration of cod-liver oil to every member of the family except himself ‘and even allowed her to give us something for our nerves called Eskay’s Neurophosphates, which arrived as samples from one of the pharmaceutical houses. But he never convinced himself about the value of medicine.’ This disenchantment with medicines led him to discover in himself a special talent for surgery, to which he devoted himself exclusively, giving up general practice.

Although he professed a poor opinion of it, Lewis Thomas’s memory is in fact an exceptionally good one, a circumstance which gives special strength and point to his historical/sociological comments on the medicine of his own day. His father attended Columbia P&S – the famous College of Physicians and Surgeons of Columbia University – at a time (1901) when medical teaching had already begun to be influenced by the ‘therapeutic nihilism’ that was the great contribution to medicine of Sir William Osler and his colleagues at Johns Hopkins University. This was the first great scientific revolution in medicine, embodying as it did that element of the scientific ethos which prohibits scientists believing events or phenomena for the existence of which there is no evidence whatsoever. Put in the very crudest terms, obviously in need of much qualification, the teaching of therapeutic nihilism was that medical treatment doesn’t do you any good. Indeed, before medical science recognised the nature and importance of hormones, and the pharmaceutical industry made them available in a clinically usable form, and before the sulphonamide drugs and antibiotics added weapons of enormous strength to the physician’s armoury, there was not much in the way of medically specific treatment for the physician to use. But during this period the improvement of anaesthesia and the introduction of the aseptic technique made it possible for surgery very greatly to prosper. As late as 1870, a prominent London surgeon had said that the abdomen was ‘forever closed to the intrusions of the wise and humane surgeon’, and as early as 1900 Berkeley George Moynihan of Leeds was so well satisfied with the progress of surgery as to declare that no further major advances were to be expected. I wonder whether the success of surgery in the early decades of the century, combined with the relative impotence of medicine, was responsible for the traditional rivalry of self-esteem between physicians and surgeons, as I suppose it may have been for the apostasy that made old Dr Thomas give up medicine for surgery.

Therapeutic nihilism, says Lewis, was a ‘reaction to the kind of medicine taught and practised in the early part of the 19th century, when anything that happened to pop into the doctor’s mind was tried out for the treatment of illness. The medical literature of those years makes horrifying reading today: paper after learned paper recounts the benefits of bleeding, cupping, violent purging, the raising of blisters by vesicant ointments, the immersion of the body in either ice water or intolerably hot water, endless lists of botanical extracts cooked up and mixed together under the influence of nothing more than pure whim.’ All these things were drilled into the heads of medical students – most of whom learned their trade as apprentices in the offices of older, established doctors. The great revolution brought about by Osler and his colleagues was to have made it clear that most of the so-called remedies in common use were likely to do more harm than good, ‘that there were only a small number of genuinely therapeutic drugs – digitalis and morphine the best of all.’ The effect of this teaching was that by the time Lewis’s father had got to P&S the centre of gravity of medical treatment had shifted to diagnosis – the recognition of specific illnesses, if possible through an understanding of the natural history of disease.

Under the chapter heading ‘1911 Medicine’ Lewis Thomas writes with Hippocratic gravity and authority on the desiderata in a graduate of one of the great medical schools after the Oslerian revolution:

  Most medical students of those decades had hard things to learn about. Prescriptions were an expected ritual laid on as a kind of background music for the real work of the 16-hour day. First of all, the physician was expected to walk in and take over; he became responsible for the outcome whether he could affect it or not. Second, it was assumed that he would stand by, on call, until it was over. Third, and this was probably the most important of his duties, he would explain what had happened and what was likely to happen. All three duties required experience to be done well. The first two needed a mixture of intense curiosity about people in general and an inborn capacity for affection, hard to come by but indispensable for a good doctor. The third, the art of prediction, needed education, and was the sole contribution of the medical school; good medical schools produced doctors who could make an accurate diagnosis and knew enough of the details of the natural history of disease to be able to make a reliable prognosis. This was all there was to science in medicine, and the store of information which made diagnosis and prognosis possible for my father’s generation was something quite new in the early part of the 20th century.

To this we must add that the physician required a close knowledge of what good nurses were able to do (Lewis’s mother had trained as a nurse): ‘The nurses had their own profession, their own schools and their own secrets.’

Lewis’s father is the protagonist of the chapter ‘1911 Medicine’: Lewis himself steps into the limelight in ‘1933 Medicine’. There was not then today’s fierce competition to enter medical school, and although Lewis’s record at Princeton was only ‘middling fair’, he was received into Harvard, perhaps (in the usage of the day) with a bit of help from his parents’ friend, the admirable Dr Hans Zinsser, who was later to write Rats, Lice and History. Though Lewis’s education was not unlike his father’s in principle, a great flowering of medical science in physiology and biochemistry, assisted by microbiology and immunology, had taken place since his father’s time and ‘transformed our understanding of the causation of major infectious diseases. But the purpose of the curriculum was, if anything, even more conservative than thirty years earlier.’ Its purpose was to teach the classification and recognition of disease entities, now in their laboratory as well as their clinical manifestations: ‘the treatment of disease was the most minor part of the curriculum, almost left out altogether.’ Pharmacology had to do with the mode of action of a handful of useful everyday drugs, such as aspirin (the discovery of the mode of action of which was the work of the past few years), morphine, barbiturates and digitalis, plus a few others. Lewis could not remember any occasion upon which his instructors referred to the contents of the thin book called Useful Drugs. Indeed, he did not ‘remember much talk about treating disease at any time in the four years of medical school except by the surgeons’.

Their own classmates were probably the most important influence on Harvard medical students in Lewis’s day, and it was through their anxious colloquies that third and fourth-year students came to realise that they didn’t know much that was really useful and that ‘we could do nothing to change the course of the great majority of the diseases we were so busy analysing, that medicine, for all its façade as a learned profession, was in real life a profoundly ignorant occupation.’

Happily any danger of disenchantment with medicine was obviated in his fourth year when, during his clinical clerkship at Beth Israel, he watched with delighted admiration the conduct of a complete physical examination by Professor Blumgart. Blumgart was an enormously perceptive physician with great intuitive powers – by which I understand a man who finds his way to a conclusion along logically unscripted pathways. Moreover, Lewis remarks that, so far as he knew, Blumgart was never wrong, not once. But he can recall ‘only three or four patients for whom the diagnosis resulted in the possibility of doing something to change the course of the illness, and each of these involved calling in the surgeons to do the something ... For the majority, the disease had to be left to run its own course, for better or worse.’ This being so, it is easy to see how there quite quickly grew up, and why there still persists, a sort of tension between physicians and surgeons, especially among people who are not very good at either medicine or surgery. Physicians have long thought themselves the patricians of medical practice, choice spirits altogether more intellectual and refined than those bustling, sanguine, adventurous and self-confident surgeons who often did more for their patients than the physicians could.

Two of the five principal services of the Boston City Hospital, ‘the city’s largest, committed to the care of indigent Bostonians’, were staffed by Harvard Medical School, and when Dr Francis Weld Peabody, reputedly the best of its physicians, founded a clinical research centre with the Thorndike Memorial Laboratories on the hospital campus, the hospital became an irresistible attraction to the brightest physicians. By the time Lewis Thomas got there in 1937, the staff was formidably talented, their names still remembered for their contribution to the causal interpretation and (by means of liver extracts) treatment of pernicious anaemia. The Thorndike laboratory became a model for establishing a working liaison between laboratory and ward.

It was in the mid-1930s that the great gunturret of scientific medicine swung round to train upon infectious disease. If treatment could be started early enough in the course of the disease, Ehrlich’s neoarsphenamine was effective in the treatment of syphilis. The great leap forward, however, was the development out of the dyestuff prontosil of the anti-bacterial substance paraaminobenzene-sulphonamide (sulphanilamide). This was the founder member of the great sulphonamide family of drugs, the oral administration of which would control puerperal sepsis and streptococcal meningitis. In later years, the triumphant success of these synthetic bacterials had the odd and unexpected effect of retarding the development of penicillin, because when money was sought to promote research into such antibiotics, wise guys on grant-giving committees announced that the future of antibacterials lay with synthetic organic chemicals such as Gerhard Domagk had introduced and not with obscure medieval-sounding nostrums like extracts of fungi.

In this period, so Lewis tells us, ‘immunology was beginning to become an applied science.’ This took me aback: for immunology, though not then so described, scored its first triumph with the success of variolation – that is, deliberate infection with a pustule from a mild case of smallpox in order to protect against the virulent disease – but the first consciously immunological procedure was the raising of antibodies against pneumococci using the purified polysaccharide capsules of the bacteria to stimulate antibody formation.

Antibodies were not then an unqualified success – and never became so, the trouble being that the vehicle of the antibody is necessarily a blood serum such as horse serum, which can arouse overwhelming and sometimes fatal anaphylactic reactions in those into whom they are injected. Lewis recounts many of the medical triumphs that preceded or accompanied the period of his internship at the Boston City Hospital: pellagra became curable; insulin had been isolated by Banting and Best; treatment with liver extract removed pernicious anaemia from the roll of uniformly fatal diseases. Lewis makes it all sound, as indeed it was, a great time for a medical scientist to be alive, for here were modern secular miracles: sulphanilamide, for example, snatched from what would otherwise have been certain death patients already moribund from pneumococcal and streptococcal septicemia. For an intern, it was like the opening of a new world: ‘We had been raised to be ready for one kind of profession, and we sensed that the profession itself had changed at the moment of our entry.’

Lewish thought of his internship quite simply as ‘the best of times’, despite the cruelly hard work, the long hours and the meagre pay. This last was not a grave embarrassment. None of the interns was married and there was no time to spend money. Two blood donations a month at $25 a time ‘kept us in affluence’ – and in liquor too, for a state law stipulated that a blood donor was entitled to a pint of whisky. The most junior intern (‘the pup’) spent his 24-hour day collecting specimens of blood, urine, faeces, spinal fluid and sputum, and doing all the laboratory diagnostic work. Two further trimesters, each with special responsibilities, completed the internship; the next rung on the ladder was Assistant House Physician, and then, after 15 months’ service, House Physician.

I was pleased to read in Lewis Thomas an account of something a layman is likely to learn about only from fiction: the nature of ‘one of the great phenomena of human disease – the crisis’, as it might occur in a young adult victim of lobar pneumonia. Typically, the disease ran ten to 14 days with a high fever each day, the patient suffering more and more chest pain and getting more and more alarmingly exhausted, and nearer and nearer the shores of Lethe. If the specific antibodies made by or injected into the patient prevailed over the pneumococci, then one day the patient’s temperature would plummet from 106 degrees to normal while he sweated copiously. He would then announce that he felt better and would like something to eat.

A second great emergency was diabetic coma. If the diagnosis was right, and the appropriate treatment given, recovery was certain. All possible help was sought and ‘the senior visiting physicians came across the ramp from the Thorndike on the run.’ Then there was acute heart failure. There were only three ways of coping with it, ‘not always effective and never in any sense curative’. The first was to withdraw a pint of blood from an arm vein to reduce the hydrostatic burden on the heart; the second was to inject digitalis – a nice matter, for too little would be ineffective and too much toxic; the third expedient was breathing oxygen. Syphilis, even if recognised early enough in its course, made an intern’s heart sink at the prospect of months or years of administering arsenicals, mercurous compounds and bismuth with all the attendant risks of toxic side-effects. When the spirochaetes reached the brain nothing could be done. Although syphilis is again on the increase, it is now manageable because of the susceptibility of the spirochaete to penicillin.

Alcoholics were sufficiently numerous for the City Hospital to set up a 40-bed ward just for them. Delirium tremens was as bad a sight as anything that came an intern’s way. The treatment was a huge dose of paraldehyde, vitamin B, liver extract and ice packs to reduce the fever: ‘That was it for the DTs, and we saw a lot of deaths.’ One death at the City Hospital was the outcome of what Lewis describes as the worst mistake he ever witnessed. A young black musician was admitted shivery and apathetic – ostensibly a victim of the pneumonia just then in season. In the event, malignant malaria was diagnosed – but too late for the administration of quinine, which might have saved him. How on earth did he get malaria, having regard to the fact that the anopheline mosquito shuns Boston in the winter? The young musician was a heroin addict, accustomed to parties at which the needle was passed from hand to hand. The medical staff felt guilty and ashamed, as William Osler said they should in the first sentence of the chapter of his textbook devoted to malaria. ‘It was a bad day for Harvard.’

Lewis’s thoughts were not then and are not now wholly preoccupied by the day-to-day practice of contemporary medicine: his mind restlessly seeks philosophic or philological problems to engage in. ‘What did doctors do?’ Lewis asks, reflecting that plague, typhus, tuberculosis and syphilis were representative of those many infections whose progress was rapid and whose outcome was usually lethal. For one thing, they practised a little magic, ‘dancing around the bedside, making smoke, chanting incomprehensibilities and touching the patient everywhere. This touching was the real professional secret, never acknowledged as the central, essential skill.’ Lewis rates touch as the oldest and most effective act of healing. ‘Some people don’t like being handled by others, but not, or almost never, sick people’: ‘part of the dismay in being very sick is the lack of close human contact.’ In the course of time, touching, like everything else in medicine, became more specialised and refined, and turned into ‘palpation’ – feeling for the tip of the spleen, or the edge of the liver – or into a thumping of the chest in order to ascertain whether the sound was dull or resonant. The gift possessed by these doctors who began the laying-on of hands was probably the gift of affection. Certainly people who do not like other people very much would have been likely to stay away from an occupation that required touching. Touching reached its highest point, Lewis thinks, in the practice of laying the naked ear against the front or back of the chest, adopted as soon as it came to be known that heart sounds could be very informative. However, the tendency of technology to increase the distance between doctor and patient, which began with the introduction of the stethoscope in the 19th century, has now gone so far that a physician may remain in his office while his patient is in another building. Physical contact is confined to a perfunctory handshake: ‘medicine is no longer the laying-on of hands, it is more like the reading of signals from machines.’ The mechanisation of scientific medicine is here to stay, but the patient may well feel that the doctor is more interested in his disease than in himself as a person. In his father’s time, Lewis remarks, talking with the patient was the biggest part of medicine, for it was almost all there was to do.

Old Dr Thomas’s professional observations on the work of nurses, combined with his good sense in having married one, gave him ‘a deep and lasting respect for the whole nursing profession’. As an experienced, longtime, virtually award-winning hospital patient myself, I can only agree. In Florence Nightingale’s day, nurses were looked down upon as loose women and this may account for the hospital tradition that nurses must be kept occupied the whole time: in the unlikely event of their being momentarily unoccupied, work must be found for them. This is fully in keeping with Dr Thomas Arnold’s teaching on the way to treat public-schoolboys. The reverend doctor’s message to mankind was that if schoolboys were unoccupied for more than two minutes they would inevitably bugger each other. I share with Sir John Betjeman the fate of having been educated at a public school so steeped in the Arnold tradition that, when we were there, water closets were doorless: but perhaps the Laureate was exaggerating when, later in life, he said that he did not have a bowel movement for three years.

I went into a big London teaching hospital for a minor operation about 1935 and was horrified to see the way work was found for nurses: hospital bandages and dressings were packed into cylindrical metal drums for sterilisation by superheated steam. These drums were made of nickel-plated copper and it was a rule that they should be kept dazzlingly polished at all times, so that already over-worked, pale and tired-looking nurses could be seen in the ward at all times with little pots of metal polish, rubbing, rubbing and rubbing away. The spirit of Dr Arnold still glared so brightly out of the eyes of the senior nurses that they would have judged it bad for discipline if all that polishing had been done away with, if, for example, the obvious solution of using oxidised metal steriliser drums had been adopted.

I was specially pleased to see that Lewis Thomas devotes a chapter to neurology, since this is the field in which, as a hospital patient, I specialised. Neurology today is very like medicine in general fifty to a hundred years ago, in its preoccupation with interpretation and diagnosis and the relative backwardness of treatment. But in Lewis Thomas’s day, neurology was undergoing a transformation: penicillin and the antibiotics generally have made brain abscesses less of a threat than hitherto and the pharmacologists have devised effective anti-convulsant drugs. Multiple sclerosis is still a most terrible evil, though long before such thoughts became fashionable, Lewis Thomas formed the opinion that multiple sclerosis was an auto-immune disease. This is still the best aetiological bet upon which new schemes of treatment are constantly being devised and tried out. Meanwhile myasthenia gravis, another form of creeping paralysis, has been shown quite definitely to be autoimmune in character and, as such, therapeutically manageable. In addition, the coming of cryosurgery (the destruction of tissue by exposure to temperatures reaching 200 degrees below zero Celsius) and of computer-assisted tomography (CAT) for finding out what is wrong inside has added greatly to the skills of the neurosurgeon. These, and later on the recognition of our own endogenous analgesic drugs – the endorphins – have made neurology for Lewis Thomas the most fascinating field of medicine. Lewis is authoritative on the subject of cancer, in a chapter devoted to which he reaffirms his belief and hope that the notion of immunologic surveillance will turn out to be valid. He also believes that cancer is not a generic name for a whole variety of different diseases, each of which has a different aetiology and requires a different treatment: cancers have enough in common to justify their being thought of as an aetiological entity.

Lewis Thomas held an unexpectedly large number of administrative appointments: he has been departmental head, dean, president and chancellor. I say ‘unexpected’ because Lewis Thomas derives no pleasure from the exercise of power and has never had need to advance his career by such onerous and time-consuming means. Only duty, then, can ever have been his motive for taking administrative office and one cannot but honour him for dong so. Writing on ‘the governance of a university’, he is at his sparkling best:

How should a university be run? Who is really in charge, holding the power? The proper answer is, of course, nobody. I know of one or two colleges and universities that have actually been tightly administered, managed rather like large businesses, controlled in every detail by a president and his immediately surrounding bureaucrats, but these were not really very good colleges or universities to begin with, and they were managed this way because they were on the verge of running out of money. In normal times, with institutions that are relatively stable in their endowments and incomes, nobody is really in charge.

It is natural to ask what kind of science we should expect from a man who writes and thinks as Thomas does. The answer is something exceptionally perceptive and witty, and unexpected in its juxtaposition of ideas. His first field of interest is that of immunological surveillance, as popularised by the writing of Sir Frank Macfarlane Burnet, an idea so clarifying that almost everyone in the business wants it to be valid. The idea can be said to grow out of a consideration of the teleology of the process by which foreign (that is, ‘non-self’) organ tissue grafts are recognised as such and rejected by an immunologic process. Lewis Thomas formed the opinion that the rejection of grafts was a tiresome by-product of the existence in the body of a monitoring system of which the primary purpose was to spy out and identify non-self variants among the cells in the body that might give rise to malignant growths which could then be reacted upon by lymphocytes much as foreign grafts are acted upon and rejected. This is a lovely idea and it ought to be true, but it is not universally accepted: there are even doubts today as to whether tumours are normally destroyed by a bona fide immunologic process – doubts that can only be resolved by an experimentum crucis which, though I believe it to be experimentally feasible, has not yet been performed. Immunological surveillance has nonetheless been an enormously fertile theory, by means of which we have learned a great deal more about the nature and behaviour of tumours than we should otherwise have known.

The second of my favourite among Lewis Thomas’s ideas could also be deemed to have a teleological origin. It is well-known that living tissues cannot normally be transplanted from one human being to another, or from one mouse to another, or from one goldfish to another. This is because all these animals differ from others of their kind in the make-up of the genes that control transplantability. These differences are inherited and the genes that control them form a so-called polymorphic system (a stable subdivision of the population into different genetic types that persist from generation to generation in roughly the same proportions). This is true of blood groups, too.

What is the point of this polymorphism and what keeps it going? This is a question that must be asked of every polymorphism, and is often answered. In collaboration with a cancer research worker from his own diocese, the Sloan Kettering Institute, Dr Edward Boyse, a man cast in much the same mould as himself, Thomas propounded the idea that these ingrained differences in tissue transplantation groups determine mating preferences.

This is something that could only be mediated through smell: mice which have different make-ups with respect to genes affecting transplantation must smell different from each other. If this difference in smell does indeed exist, the reasoning went, a dog must be able to tell one mouse from another, even if the mice differ by only a single gene. Put in this way, the hypothesis was clearly testable. I watched an enormously informative test in progress at the Medical Research Council’s Clinical Research Centre in London – happily situated near the Hendon Police College, widely regarded as the world’s greatest centre for the training of tracker dogs. What I found so deeply instructive was the system by which the tracker dogs were trained. Human mothers and pedagogues are reconciled to the notion that training is the outcome of a judicious blend of rewards and punishments. Unless I was being unduly inattentive, these tracker dogs were trained only by rewards, which took the following form. When the tracker was given some nesting material from a mouse’s cage so as to get the mouse’s smell into its mind, it was then set the task of picking this mouse out from a number of others. If it did so, it would bound back to its trainer, who thereupon patted the dog enthusiastically, scratching its tummy and exclaiming inanely: ‘There’s a good dog!’ (Pat, pat, tickle, tickle.) ‘Who’s a good dog, eh?’ (Pat, pat.) ‘There’s a good dog.’ (Tickle, tickle.) And so on. I did not take part in the execution of this experiment: I merely ‘assisted at the experience’, as our French colleagues say. I still wonder what lesson we can learn from the apparent truth that, for these tracker dogs, the withholding of approval is punishment enough.