Peter Medawar was a great biologist whose research helped to make possible the transplantation of human organs. He also thought profoundly about the methods, the meaning, and the values of scientific research, and he published his thoughts in books and essays that are models of clarity, style, and wit. Born in 1915 in Brazil of a Lebanese father and an English mother, he received his education in England and made his career there. He became a full professor at thirty-two, a Fellow of the Royal Society at thirty-four, a Nobel Laureate at forty-five, and head of Britain’s largest medical research laboratory at forty-seven. At fifty-four, when his intellectual powers and capacity for work seemed inexhaustible, a cerebral hemorrhage destroyed the right half of his brain, but it did not impair his determination, his vitality and optimism. Three years later he was back at his research and literary work, and he lectured around the globe. In 1980 a cerebral thrombosis set him back severely. Again he recovered and wrote more papers and essays as well as a hilarious autobiography which makes even his tragedy an occasion for laughter. 1 In 1985, another series of strokes robbed him of his ability to speak clearly and of most of his eyesight, and in 1987 they finally killed him.

He never wanted to die, severely crippled though he was. In the last of his essays, now collected and published under the title The Threat and the Glory, he pours scorn on the crumbling baroque edifice of Freudian psychoanalytic theory that postulates a death instinct, “the most deeply unbiological explanatory concept in Freud.”

The tenacity of our hold on life and the sheer strength of our preference for being alive whenever it is an option is far better evidence of a life instinct than any element of the human behavioral repertoire is evidence of a death instinct. It is odd, then, that nothing in modern medicine has aroused more criticism and resentment than the lengths to which the medical profession will go to prolong the life of patients who need not die if any artifice can keep them going…. Charity, common sense, and humanity unite to describe intensive care as a method of preserving life and not, as its critics have declared, of prolonging death.

Medawar was tall, with “the pride of bearing that comes from good looks known to be possessed”2 and powerfully built, good at tennis and cricket. He was outgoing, vivacious, sociable, debonair, brilliant in conversation, approachable, restless, and intensely ambitious. From his student days he was determined that none of human knowledge should be beyond his grasp; for example, he declared Bertrand Russell’s formidable monograph on mathematical logic, the Principia Mathematica, to have been the book that influenced him most when he was a student at Oxford.

Later he fell under the spell of the philosopher Karl Popper, whose book Conjectures and Refutations taught him the scientific method that he adopted and popularized in his writing. According to Popper, scientists do not derive general laws from observations, but they formulate hypotheses which they then test experimentally. This method leads them gradually closer to the truth. Popper’s view that imagination comes first had a strong appeal for Medawar, since it implied that a scientist is not a robot who turns the handle of discovery, but a creative spirit on a par with artists and writers. Medawar called Popper’s “the hypothetico-deductive method.”

Popper gave explicit form to a method already used by the greatest scientists in the past. For example, in 1856 Michael Faraday wrote about the propagation of light waves through the supposed ether: “I have struggled to perceive how far…experimental trials might be devised, which…might contradict, confirm, enlarge, or modify the idea we form of it, always with the hope that the corrected or instructed idea would approach more and more to the truth of nature.”3

Medawar allowed nothing to deflect him from the pursuit of knowledge, except possibly laughter. He rarely relaxed, did not believe in holidays, and continued his research even while heading an institute of several hundred people. He maintained that a lot of his work was “as good as a rest,” and he prided himself on wasting no time, but neither Russell’s logic nor Popper’s hypothetico-deductive method saved him from wasting several of his best years on experiments that proved to be futile. He had formulated bold hypotheses about the spread of pigments in animals’ skin, which is a fundamental problem related to growth and differentiation. He then devised ingenious experiments to test his hypotheses, but he blinded himself to the possibility that he might be looking at the wrong kind of cells. As I have learned to my own cost, one can become so enamored of one’s ideas that doubts aroused by inconsistent results are stilled with far-fetched explanations rather than being allowed to overturn basic premises. Medawar preached that research is a passionate enterprise, but he did not warn scientists that that very passion can lead them into a trap.


What did it feel like to be married to such a man? Like Enrico Fermi’s widow Laura, who began her light-hearted biography of the great physicist while he was still alive,4 Jean Medawar’s biography, called A Very Decided Preference, draws an affectionate and bemused cartoon of Peter instead of chiseling him in marble. He told his young bride, pretentiously, that she had first claim on his love, but not on his time, made her buy her own wedding ring and often also her own Christmas presents. So preoccupied was he with his work that Jean had to be both father and mother to their four children. He had no patience with real people’s emotional problems, but was spellbound when he heard them transformed into music in Wagner’s operas. Wotan bidding Brünnhilde good-bye in Die Walküre stirred him more than his own daughter leaving home for months. When Jean reproached him for having hardly noticed that she had gone, he explained that “his emotions were stirred by art,” the sort of priggish remark that Mr. Casaubon in Middle-march might have made to Dorothea.

Medawar’s emotions were stirred by Wagner and Verdi (hardly by Mozart), but apparently not by great painters until he reached middle age and paid his first visit to the Frick Museum in New York. In his review of the fifteenth edition of the Encyclopedia Britannica, he scoffs at the entries for Sisyphus, Tantalus, or Leda as superfluous, oblivious that much of the visual arts and literature was inspired by classical mythology.

Young Medawar proudly told a friend, “My mind, you know, never lets me rest,” but old Medawar wrote modestly that “It is a natural tendency of the mind to come to and remain at a complete standstill. This is a principle of Newtonian stature.” In a hospital, books “are crucially important for keeping the mind in working order. Some serious works should therefore be among them. Remember, however, that if you didn’t understand Chomsky when you were well, there is nothing about illness that can give you an insight into the working of his mind.” Medawar excelled in such sallies, and Jean tells us that he would laugh out loud as he wrote them.

Her biography begins with the tragic episode in Exeter Cathedral, when he fell “from a pinnacle of achievements into a state very near to death.” He had been invited to give the presidential address at the annual meeting of the British Association of the Advancement of Science, and he chose that honorific occasion for a passionate profession of his faith in science. He named his lecture after Francis Bacon’s New Atlantis, an island kingdom where the Merchants of Light establish “the noblest foundation that ever was on earth” whose object is “the knowledge,…and the secret motions; and the enlargement of the bounds of human empire: THE EFFECTING OF ALL THINGS POSSIBLE.” The purpose of his address, Medawar said, was “to draw certain parallels between the spiritual and philosophic condition of thoughtful people in the seventeenth century and in the contemporary world.” The Thirty Years War on the continent of Europe and the Civil War in England brought “a period of questioning and irresolution and despondence,…a failure of nerve.” Besides, people believed that the Biblical apocalypse was at hand, much as we fear, with more reason, man’s destruction by nuclear war. “Then as now the remedy for discomforting thoughts was less often to seek comfort than to abstain from thinking” (a typical Medawar aside).

In the second half of the seventeenth century the belief that the rational pursuit of science could improve the human condition engendered a new spirit of optimism.

The repudiation of the concept of decay, the beginning of a sense of the future, an affirmation of the dignity and worthiness of secular learning, the idea that human capabilities might have no upper limit, an excellent recognition of the capabilities of man—these were the seventeenth century’s antidote to despondency.

Medawar calls for a similar antidote in our time. “We wring our hands over the miscarriages of technology and take its benefactions for granted.” “The real trouble is our acute sense of human failure and mismanagement, a new and…oppressive sense of the inadequacy of man.” Nevertheless “to deride the hope of progress is the ultimate fatuity, the last word in poverty of spirit and meanness of mind.”5

Jean relates that he had worked on this lecture for months, and had moved her to tears when he tried it out on her at home. It still is one of the most eloquent and erudite pleas for science that I know.


Two days after delivering that address Medawar was asked to read the lesson to a large congregation of the British Association assembled in Exeter Cathedral. He chose a passage from chapter seven of the Wisdom of Solomon:

For Wisdom, the fashioner of all things, taught me, for in her there is a spirit that is intelligent, holy, unique, manifold, subtle, mobile, clean, unpolluted, distinct, invulnerable, loving the good, keen, irresistible, beneficent, humane, steadfast, sure, free from anxiety, all powerful, overseeing all, and penetrating through all spirits that are intelligent and pure and most subtle.

He started to read more slowly. Gradually he spoke as if the words were costing him a colossal effort.

For wisdom is more mobile than any motion; because of her pureness she pervades and penetrates all things.

At that moment his speech began to slur, and he collapsed with a cerebral hemorrhage.

It was a fall from the heights of a brilliant career to helpless dependence on life-support machinery, doctors and nurses, and above all on Jean, whose sheer determination to conceal her constant anxiety and to restore Peter to full activity fortified his own “very decided preference for staying alive.”

Jean was the daughter of a much-loved Cambridge doctor who had died of chronic bronchitis at almost the same age. She won a scholarship to Oxford, studied biology, and after graduation, began research in cell biology. On hearing that she had become engaged to a man who was half-Lebanese, her aunt cut off the allowance she had given her for her studies; her mother warned her of having black babies; a well-known writer told a friend of her father’s that she would not be received into society, and a doctor friend of her father’s, asked to treat a small infected wound on Peter’s elbow, viciously demonstrated it to his students as a venereal ulcer characteristic of syphilis and told Jean not to kiss him. Such were the xenophobia and racism prevalent in England in the 1930s. Later Medawar’s scientific accomplishments and superb command of the English language made people forget his foreign origins, and his fateful appointment to the presidency of the British Association shows that he had become part of the Establishment.

Raising a large family and keeping a hospitable house took up all Jean’s energy until a trip to Moscow with Peter in 1955. She writes: “In England…you got credit for running a good home, looking after your husband and keeping yourself in shape. In Russia this wasn’t enough; they wanted to know what your profession was and how good you were at it.” Therefore, after her return Jean began to work, unpaid, at an agency where legal and other advice was provided free for people in need, and at a family planning clinic where women received help and advice for contraception. In both she learned “how many people spent their lives in a state of quiet despair.” Later she became secretary and finally chairman of the Family Planning Association, as well as editor of the journal Family Planning.

She was coauthor of several of Peter Medawar’s books and thoroughly enjoyed accompanying him on his many scientific and honorific journeys. In Stockholm the Swedes made her feel that welcoming her and honoring Peter was “the one thing that they had looked forward to all the year,” and not as if they “had been delivering this kind of fairy-tale celebration every year since Alfred Nobel founded the prize.” She notes in her book that “The aura of having won the Nobel Prize seems not to fade.” She tells the reader of the good times they had together with their many friends throughout the world. Later she writes that she does not know how to describe “the cold, sick misery” of the lonely year Peter spent in a general ward of the Neurological Hospital in London’s Queens Square after his third stroke. Yet I found him there still joking, and Jean took him out in a wheelchair to hear Karl Popper deliver the first Medawar Lecture to the Royal Society. Medawar said that “People look at you with a new respect when you have been there and back.”

The title of Peter Medawar’s collected essays, The Threat and the Glory, is taken from his review of several books on genetic engineering that appeared in the New York Review in October 1977 under the title “Fear of DNA.” These fears have not diminished, even though there has not been a single mishap to substantiate them, and the benefits have multiplied. Medawar disposes of the fear that gene technology will make it possible to change people’s characters and personalities in order to create a nightmarish Brave New World of brainy masters and stupid slaves. He argues that this could have been embarked upon at any time in the past thousand years “merely by applying the most powerful of all forms of biological engineering—Darwinian selection—to a population—mankind—known by its open breeding system, lack of speciation, and rich resources in inborn diversity to be perfectly well able to respond to the empirical acts of the stockbreeder.”

If these enormities have not been perpetuated or even seriously attempted hitherto by the comparatively straightforward and empirically well-understood methods available for their execution, why should we now begin to fear that enormities as great or even greater will be executed by the much more costly and technically more difficult procedures of genetic engineering?

Besides, Medawar points out that the technology needed to fill the mind with untruth, with a resistance to new learning and to anything that might conduce to improvement has been known for 5,000 years or more and is known as “education.”

In another essay “Biology and Man’s Estimation of Himself” Medawar disputes that the propounding of Darwin’s theory of evolution was a great affront to human dignity, but I doubt that he was right. Noel Annan’s Life of Leslie Stephen relates the profound shock that Victorians experienced when they felt their religious beliefs shaken by the Origin of Species; I also remember the outrage that Jacques Monod’s book, Chance and Necessity, recently caused among the French, even though Monod merely restated Darwin’s theories in molecular form.

Medawar’s review of the sociologist Harriet Zuckerman’s The Scientific Elite contains observations on the great scientists who did and those who did not win the Nobel Prize. I had believed American laureates to be, like most other scientists, of working-class or lower middle-class origins, but in fact 90 percent of their fathers were professional men, proprietors or managers. Half of them had worked either as students, post-doctoral fellows, or junior collaborators under older laureates, but they owed the prize to the older men’s good teaching rather than their sinister influence on the Nobel committees in Stockholm. Medawar writes that “the laureates who would have pleased Nobel are those to whom the award gave a terrific fillip to proceed with their research” (like Medawar himself) but Nobel would have been dismayed if “the benefaction intended to put its recipients beyond the reach of want had, in reality, deprived them of any further incentive to continue with scientific research.” These people spend their time traveling from conference to conference, with platitudinous titles like “Man and the Universe,” “Science and Culture,” or “Environment and the Future.” Fortunately they are in a small minority, but it has not escaped my notice that the sly organizers of such meetings flatter Nobel Laureates by persuading them that their presence is essential for the survival of mankind, and then exploit their promised attendance to extract funds from gullible benefactors.

Medawar’s bêtes noires are psychoanalysts and traders in IO. He never missed an opportunity of deriding Freud and his faithfuls as, for example, in his essay on Darwin’s illness in which he ridicules the psychoanalysts who uncovered “a wealth of evidence that unmistakeably points” to the idea that Darwin’s chronic indigestion, cardiac symptoms, and lack of physical energy were “a distorted expression of the aggression, hate and resentment felt, at an unconscious level, by Darwin towards his tyrannical father…. As in the case of Oedipus, Darwin’s punishment for the unconscious parricide was a heavy one—almost forty years of severe and crippling neurotic suffering….” Medawar comments sarcastically:

These deep and terrible feelings found outward expression in Darwin’s touching reverence towards his father’s memory, and in his describing his father as the kindest and wisest person he ever knew: clear evidence…of how deeply his true inner sentiments had been repressed.

The real cause of Darwin’s chronic malaise was probably a parasitic infection that he contracted in his travels through South America.6

In Popper’s view psychoanalytic and Marxist theories are equally unscientific, because both are self-fulfilling and neither can be falsified experimentally. I wonder what Medawar would have made of R.C. Lewontin’s dogmatic and unprovable assertion that “Darwin’s theory of evolution by natural selection is obviously nineteenth-century capitalism write large, and his immersion in the social relations of a rising bourgeoisie had an overwhelming effect on the contents of his theory.”7 Marxism may be discredited in Eastern Europe, but it still seems to flourish at Harvard.

In his review of W. Broad and N. Wade’s book Betrayers of Truth, Medawar relates the findings of the English psychologist Sir Cyril Burt that working-class children have lower IQs than children of the professional and managerial classes. For many year Burt’s publications influenced educational policies until Leon Kamin and Oliver J. Gillie discovered after Burt’s death that he had faked his data. Medawar believes that “there was no effective check of Burt’s findings, because he told the IQ boys exactly what they wanted to hear.” Medawar then asks how the young scientists with obvious intelligence and ability mentioned in Betrayers of Truth had supposed they would get away with sensational results that were based on fraudulent experiments. Efraim Racker, a professor of biochemistry at Cornell University, was himself a victim of fraud committed by one of his own graduate students. He describes that student as outstandingly able and believes that he and others like him were mentally unbalanced, suffering from a kind of schizophrenia that closed their minds to the likely consequences of their actions.8

Once I became the victim of scientific fraud, committed by a student who was told by his professor what result we expected him to find, and promptly found exactly that. I doubt that the student was schizophrenic, but probably just naive and anxious to please. Medawar points out that if among the thousands of scientists there are just a few odd crooks, then he would draw “a clear distinction between the scientific profession and the pursuit of mercantile business, politics, or the law, professions of which the practitioners are inflexibly upright all the time”—another characteristic sally that must have drawn a laugh as he wrote it. Medawar’s sharp pen punctured obscurantism, pomp, mysticism, cant, pseudoscience, and high-flown verbiage without meaning posing as profundity, as in Pierre Teilhard de Chardin’s book The Phenomenon of Man.9 In an innuendo about semantics he writes: “The innocent belief that words have an essential or inward meaning can lead to appalling confusion and waste of time. Let us take it that our business is to attach words to ideas and definitions, not to attach definitions to words.” Well said.

He lashed out at “geneticism” as “an application to human affairs of a genetic understanding which is assumed to be much greater than it really is.” He dismissed eugenics as lacking any scientific foundation and would have indignantly rejected the recent claim that criminal behavior is inherited as just another example of geneticism.

N.A. Mitchison’s brief biography of Medawar contains an excellent account of his scientific work. Medawar’s first great discovery was that the rejection of skin grafts from a donor is an immunological reaction, a reaction mediated not by antibodies, but by white blood cells, which James Gowans later identified as lymphocytes. Medawar wrote that these cells behaved

like the chorus in a provincial production of Verdi’s Faust; lymphocytes in the bloodstream at any one moment disappear behind the scenes and re-enter by another route.

Medawar asked how lymphocytes distinguish between self and nonself. This led him and his colleagues R.E. Billingham and L. Brent in the mid-Fifties to their second great discovery. They found that animals can be made tolerant to grafts of foreign tissue if they have been immunized by an injection of such tissue while still in their mother’s womb. The mere fact that animals can be made tolerant to foreign grafts raised the hope of inducing such tolerance in humans and encouraged experiments on the transplantation of organs.

At first this was possible only between identical twins. Later, Medawar and his colleagues felt encouraged that steroids delayed the rejection of skin grafts. They then tried to immunize rabbits with mouse lymphocytes, and injected the immune serum of the rabbits back into the mice. This suppressed the lymphocytes’ attack on foreign grafts, at least for some weeks or months.

His first attempts to develop this method for human use were overtaken by the discovery that cyclosporin, a compound isolated from a fungus at the Sandoz Laboratories in Switzerland, had a powerful suppressive effect on lymphocytes in animals and a low toxicity. Roy Calne in Cambridge, England, has pioneered its use and that of other immuno-suppressive drugs in humans. He was able to tell Medawar before his final series of strokes that one of his life’s great aims, to make human beings tolerant of transplanted organs, had at last been achieved.

This Issue

August 16, 1990