Medawartime

My first encounter with Peter Medawar revealed something about us both. When he was the new Mason Professor of Zoology in the University of Birmingham I was a student at University College, Nottingham, and one of my tasks as president of the student Zoological Society was to give votes of thanks to visiting speakers. So when I learned that one Dr Peter Medawar would be speaking on the subject of individuality in animals, I sat down and carefully prepared a short speech which I proposed to deliver with every appearance of total spontaneity. Fortunately for my vote of thanks, part of the previous term had been spent studying animals such as sea anemones and sponges which merge into colonies, where the issue of who, or what, was really the individual was both entertaining and, we were assured, significant.

Our speaker arrived, his lecture was delivered and listened to by all with admiration – save me. In my case, admiration was rapidly replaced by horror. For with every word spoken it was clear that my vote of thanks really was going to be spontaneous. Peter Medawar was talking, not about esoteric sponges, but about how, and why, skin transplants grafted from one individual to another would always be sloughed off and how this might possibly be circumvented. The problem, as the war had shown, was crucial. Battle of Britain pilots, suffering from third-degree burns, had in some cases lost so much skin that there was no alternative but to transplant skin from a ‘foreigner’, a process that gave only temporary relief: the foreign tissue always ended by being rejected.

I stumbled to my feet and as best I could delivered myself of a short spontaneous speech. Three hours later, after the ritual of sherry and dinner, staff and students were waiting on the steps for the taxi that would take our speaker to the railway station. As the taxi drew up, he turned to me and said: ‘Votes of thanks are notoriously difficult to do and I think you did it superbly.’

This kind gesture to someone very unimportant, in circumstances where most people would have stayed chatting up their intellectual peers, was – as I was to learn over the years – typical of Peter Medawar, and as my contacts with him grew, two elements of that encounter also continued to develop. One was my ever-increasing sense of this personal charm and kindness; the second his interest in, contributions to and passionate conviction about the problem of individuality, not now in animals so much as in human beings.

I may not have heard of Peter Medawar in 1948 but I soon did – in a variety of ways and in a variety of places. My own career as a research scientist quickly faltered: after one year of research at Oxford it was obvious that I lacked that obsessional interest in the world and the desire to find out just how it works – an obsession which must inevitably lead to the exclusion of many other things, such as a deep interest in people and a desire to find out how they work – which is required of the good scientist. ‘Most of the day-to-day business of science,’ he once reminded an assembly of scientists, ‘consists of trying to find out if our imagined world is anything like the real one. If it is not, we have to think again.’ It was the processes of human imagination and the role of the individual in these processes that fascinated me, and I was to use the words ‘imagined world’ in the title of a book I wrote on that theme. But what fascinated Medawar were the implications of his phrase ‘we have to think again.’ The skill of scientists, their individual styles perhaps, can be found in the manner in which they try to work out ways and means of deciding whether or not their imagined world is anything like the real one – i.e. in their design and execution of experiments. Medawar was not only brilliant in experimental design and execution: he was a positive genius at sensing which was the right experiment to do at any given time. He once told me that he had received a very early lesson in this respect.

As a graduate student at Oxford he had become extremely excited when reading the early papers of the distinguished Austrian/American biologist, Paul Weiss, who had transplanted the legs of a salamander from back to front and left to right and found the specificity of the original position not only retained but reflected in the very limb movements. Medawar was so entranced and intrigued by the phenomenon and what it suggested, in both theoretical and experimental terms, that he rushed up to Goodrich, who was then his professor, and urged him immediately to switch his attention to what Medawar now felt might turn out to be the most important phenomenon in contemporary biology. Goodrich looked at him with a stern and quizzical air reminiscent of Professor Kingsfield in The Paper Chase, and told him to go away and bring back Weiss’s paper in twenty years’ time, when, he explained, zoologists might be in a position to deal with Weiss’s phenomenon. What Medawar learnt on that occasion was the concept of ‘unripe time’ – a lesson he put to good use in his own work and constantly taught others. He often spoke of the really gifted scientist as the person who is not twenty steps but one step ahead of nature and the cutting edge of research, a person who can anticipate exactly where the barriers to understanding will crumble and where the new frontiers will coalesce.

Medawar’s ‘genius’, his colleague John Maynard Smith told me, ‘was a bit unexpected. He had a genius for thinking of the right experiment which I enormously envy. I don’t have it myself: I never think of the right experiment. If I do an experiment at all, it’s usually the wrong one. Nor did Haldane, of course, have any idea of how to do the right experiment. Peter also had another terribly interesting quality. If you got involved in a scientific argument with him, once he had thought of the right experiment to do, he wouldn’t go on arguing the point because he was a good Popperian. I’m always prepared to go on arguing till the cows come home. But he’d go and do the experiment, or get someone else to do it. Even if the issue wasn’t really in his field he still felt that until somebody had done the experiment it was silly to argue.’

Medawar was a brilliant, intuitive player in the game of science, as he was at bridge and chess – a person who seemed in all respects to be too lucky by half. One friend who regularly made up a bridge four every Saturday night with Medawar and his very bright, sweet mother recalls that he’d always gone home convinced that Medawar’s cards had been better than anyone else’s. ‘But actually,’ he insisted, Medawar ‘just played bridge better than the rest of us. He played a lot of games better than the rest of us. A few could beat him at chess, but he was almost impossible to beat at squash: you could never get the ball past him. The sheer physical and mental energy was formidable, amazing, and flowed out perpetually.’

Lucky or not, genius or not, the natural world would from time to time oblige Medawar to think again. In the very same year when I had been grappling with that vote of thanks, at a Congress of Genetics in Stockholm Medawar spoke with Dr Hugh Donald, who was engaged in research on cattle twins. Donald had been trying to clarify the exact distinction between identical twins (so-called because they result from the division of one egg) and fraternal ones (so-called because more than one egg is fertilised and develops in the womb). Donald wished to be absolutely certain of his classification. Medawar, as his book tells us, with a fine hubristic touch opined that this was extremely easy. All that was needed was to exchange pieces of skin between cattle twins and see how long they stuck. If they stayed on indefinitely the twins would be identical: if they were thrown off after a week or two the twins could with certainty be classified as fraternal. Medawar gave a further hostage to fortune by promising to demonstrate the technique to Donald’s veterinary staff. A few months later his bluff was called. Being now morally committed, Medawar and Rupert Everett-Billingham, his long-time friend and colleague, had to go and do the experiment and this time it was nature that called Medawar’s bluff: the results were the absolute opposite of what he had predicted. All cattle twins, no matter what, accepted skin grafts from each other for as long as the experiment continued, and some were without doubt non-identical, because some of the offspring were of different sexes.

So Medawar and Billingham had to repeat the whole experiment. Working with cows and calves in cowsheds in the foggy early morning was not the most delightful of occupations, and it had to be done not only once but over and over, and each time the results were the same. Finally, Medawar had to concede that, for some unknown reason, cattle twins were an exception to the general rule, which stated that skin grafted between two genetically dissimilar animals would be rejected.

Acceptance of what nature demonstrated has to be followed by explanation, and Medawar has always admitted that this came not as a result of any exertion on his part but from browsing through a newly-published book, The Production of Antibodies (1949), by Frank Macfarlane Burnet and Frank Fenner. Macfarland Burnet and Fenner described some remarkable work by Ray Owen, an agricultural geneticist at the University of Wisconsin, who had found that all cattle twins, whether fraternal or identical, had the same blood group. This, Owen suggested, was due to a fact known for years: that cattle twins often shared one placenta – which meant that before birth each foetus was transfused with the other’s blood. Medawar and Billingham reasoned that somehow the power to reject a foreign graft was subverted in the mutual blood transfusion that had occurred before birth. The tolerance was quite specific to cattle twins: a twin would take skin from the twin with whom he had shared a placenta, but a graft from another sibling or a parent was rejected in the usual brisk manner.

This superb – and as it turned out – entirely correct lead would provide the starting-point for a series of magisterial experiments in immunology and transplant phenomena which eventually led to the Nobel Prize. Yet John Maynard Smith recalls driving somewhere together with Medawar when he was Medawar’s student and asking him, at what he thought was an appropriate moment, what it had felt like to discover that twin cattle were the general exception to the rule. ‘We were absolutely furious,’ Medawar replied. What he was remembering was the slog of having to go to the cowshed every morning, expecting to find that the graft had been sloughed off, and finding that it hadn’t been. He thought he understood the world and now the world retaliated and showed him that he didn’t.

University College London was to provide the setting for Medawar’s classic work, which was to bring about by experimental design the immunological phenomena he and his colleague had observed in twin cattle, and provide an explanation for them. The objective was to reduce – even abolish – in laboratory animals the power to recognise and destroy genetically foreign tissues. They finally managed to produce immunological tolerance in mice: it was an acquired immunological tolerance, and it enabled the animals to accept foreign grafts. As they now realised, such tolerance had turned up before in science, having been described many times by embryologists. Though the results were announced in 1944, at a conference organised by the Ciba Foundation, it was not until nine years later that Medawar and Billingham published their discovery in Nature – a time-lag that today’s thrusting young scientific Turks would consider so cautious as to verge on professional suicide. However, the existence of immunological tolerance gave scientists and doctors both a practical and – Medawar insists – a moral boost, for people were beginning to believe that the human transplantation problem was insoluble, that using tissues or organs from unrelated donors was futile, that pilots with third-degree burns would always die from open infections. The demonstration that transplantation need not be a futile procedure had enormous consequences: it provoked an outpouring of basic biological research into immunology as well as the expansion of a whole range of surgical procedures.

If the experiment was in its way a classic, so too was the paper Medawar published in Nature. Even though scientific results are communicated in a manner that expunges all traces both of the ecstasy of creation and of its frustrations, nevertheless some scientists insist that if you know what to look for, it is possible to sense something of the individual scientist behind the written words. Medawar’s paper was to provide me with the best example of this.

Years later I followed the work of an immunologist on a daily basis, trying to assess the point at which individuality is brought to bear on scientific procedure, and I finally wrote An Imagined World. The problem I began with is simply stated: scientists come in as many varieties as Heinz soup and there is, as Peter Medawar has constantly reminded us, no one scientific method. The issue is most clearly defined if one looks at the analogies between science and chess. People as different as Boris Spassky and Bobby Fischer consistently play well and brilliantly, and also outplay each other. Since chess cannot, any more than science, be followed by recipe or rote, at some point the force of the individual character must come into play. The real question is where and how? I spent five years trying to explore this question. Finally, Dr Maria de Sousa (the Anna Brito of the book) and I sat down and tried to sum it all up. We began talking about discovery and the central problem which had started me off and she said:

‘Now you can make a contribution in science, and its resonance becomes its principal attribute. Then it doesn’t matter if you’ve made only that one contribution. You can die in peace, because the echoes will remain; the thing is there. For example, if you read Peter Medawar’s first paper on homograft rejections, its echo stays. But in immunology there are only a few papers of that quality.’

  ‘What are the qualities that make that paper echo?’ I asked.

  ‘Well, thoroughness for a start. It is absolutely thorough about one question. It goes into the analysis of that question in every possible way. It covers all techniques available at that time, and thus it has an element of technical thoroughness which makes it a real beauty, even just technicaly. Then there is the thoroughness of the thought. A great deal of thought has gone into it, based on technical knowledge. In fact, the two – the thought and the technique – become so mixed that it is impossible to define the boundary between them. Next, of course, his fineness of mind comes through in the quality of his approach to the questions. And you can pick up the quality of his mind again in his discussions of the problems. In fact, scientific papers are not devoid of human touches if you know the code, if you know where to find the various clues. In the introduction you can pick up the writer’s position in relation to his question; you pick up his individual judgment in the method he, or she, has chosen; and in the way the results are presented, you pick up the quality of mind; finally, you again pick up the fineness of mind in the discussion sections at the end of the paper, when the writer looks at his own particular problems and places them in perspective – in their relation to the problems and ideas currently in circulation.’

  ‘It should be possible, then, to look at a scientific paper and sense something of the individual who wrote it?’

  ‘If you know what to look for, yes.’

Fineness of mind, quality, perspective, judgment, have been apparent in everything Peter Medawar has done. Widely-read, educated and cultured, his scientific, philosophical and more popular writings are, at one and the same time, a delight, an education, a stimulus and a provocation. It is a privilege to spend time in his company, for he is not only a joy to read and to talk to, but he has a fantastic wit – an enormous capacity to amuse himself as well as other people. His life has, as he says in the final lines of this book, ‘by no means been without its risible aspects’, and a large number of these he has himself quite deliberately provided.

I have talked to a number of Peter Medawar’s friends. The word ‘grandeur’ constantly recurs. In the first place, it’s impossible not to look up to someone who is 6 ft 5, especially when you’re 5 ft 2. More seriously, one scientist, who now holds a very distinguished position indeed in British science, said: ‘When I used to go and see Peter in the very early days, when he was a great man and I was still struggling, I always came out of his office feeling taller. He was always very generous and encouraging. I have gone into the offices of great men and come out feeling about half my size. But Peter has that trick of making people feel very important. He has always had great style and he has always had beautiful manners. That’s just natural – a gift he’s very lucky to have. He’s a very noble man, and a lot of people look up to him for the way he has conducted his life.’

‘Kindness’, ‘charm’, ‘brilliance’, ‘wit’ are other words that make up the refrain. As with many men destined for great things, he has had appropriate amounts of ambition and his own touches of vanity, but as his colleagues insist, almost all good scientists are ambitious, with notions about priority and the rest – and Peter Medawar was no exception. But, unlike many scientists, he never kept ideas to himself or claimed those that were partially other people’s, and in any case, this aspect is very much a footnote to the general assessment of a remarkable man. Other personal traits emerge. It wasn’t so much that Medawar was intolerant of fools – which he was – as that he would avoid them whenever possible. But this was balanced by his extraordinary generosity both to his friends and to ordinary people. Above all, he is a man whom one could trust both scientifically and personally. ‘The overwhelmingly important thing about Peter is that he did actually mind about the truth. For that I am prepared to forgive him everything else,’ said one friend. ‘Not that there’s a lot to forgive actually. But you could trust him completely because you knew what he minded about. It’s always important with scientists that they have that quality, but it was just more important for Peter, because it was such a large part of him. He did bloody well mind about ideas; he still does mind, and above all he had this white-hot regard for the truth.’

The question one still wants to ask, however, is what moves, drives and motivates Medawar. It is generally agreed that only a few people – if anyone – really know anything about him at all. Friends who have known him for years recall never being able to penetrate the mask of wit. Once something personally sensitive is approached, in almost any area of his life, it is turned into a joke. Even friends who felt they have been quite close, who have worked with him, or been with him regularly, whether socially or scientifically, say that he has never expressed those hopes, fears, depressions, elations and hates that are for the most part willingly exposed in one’s other friends. So if asked what moved Medawar, they will say: a love of science, intellectual ambition, regard for the truth – and then there is a long, long pause. His resources, both intellectual and personal, are quite extraordinary, and this has clearly emerged both in his work and his life. But just how he has managed to sustain himself we may never know. The spread of the intellectual resources are almost without compare: but the person who possesses them remains hidden.

The real individual that is Peter Medawar has not only escaped us all in the past, but will escape us in the future too. Known only to one or two, he slips away like mercury at the first application of personal pressure. For a variety of reasons, even the most brilliant and painstaking of biographers will, I believe, come to share my frustration: captured by Medawar’s attractive personality and brilliant life, he will realise that the material necessary to write a genuine biography is simply not there, either because it has been quite intentionally hidden or because it was never there in the first place.

When I read Isaiah Berlin’s great essay on Vico in Against the Current I came to understand why many people, from Disraeli to Emerson, have said that history is really nothing more than biography, for Berlin describes the kind of knowledge that Vico felt history should provide – and which is sadly absent here. ‘This kind of knowledge is not knowledge of facts or of logical truths, provided by observation or the sciences or deductive reasoning; nor is it knowledge of how to do things; nor the knowledge provided by faith, based on divine revelation, in which Vico professed belief. It is more like the knowledge we claim of a friend, of his character, of his ways of thought or action, the intuitive sense of the nuances of personality or feeling or ideas which Montaigne described so well, and which Montesquieu took into account.’

Though Medawar intended this enchanting memoir to be only an intellectual autobiography, in the end even he was unable to ignore the other facets of life. He confined himself, however, to those which ‘seemed to throw some light on the human comedy or the human predicament – very often the same thing’. So the pages of this book present a vast cornucopia, from which we are invited to retrieve beautiful, rich and tasty fruit, in no discernible order. And though I enjoyed every single word, and relished every single page, I finished it feeling as frustrated as Medawar temporarily did when the experiment refused to come out according to prediction. After all this time he has revealed no more than he revealed in the Forties.

If I now could, I would tease him hard about his phrase ‘shedding light upon the human predicament’. What predicament? His has been an extremely successful life. His upbringing was sheltered and comfortable although the barbaric experience of life as a schoolboy at Marlborough could – who knows? – be one source for his ever-present reserve. But where his magnificent obsession and focused drives came from we don’t know. There’s always a price to be paid for such single-minded energy, so who paid it? Again, we don’t know. There is absolutely no room for failure here: mistakes, errors, certainly – but not failure. Why failure is not even contemplated is still an unknown. All these thoughts Medawar would call ‘disquieting’ and, as he writes in this book, for him the best remedy for disquieting thoughts is to abstain from thinking them. The unpleasant or unacceptable has always been shut out: if there is a darker side to this wonderful, lovable man, the key may lie somewhere here.

I do think this is a genuine loss – and I must make it clear that I am not referring to the details of private behaviour that are often sprinkled into biographies of great people. An understanding of the human personality at work would, at the very least, be likely to be a source of inspiration and encouragement to the many young aspiring scientists who may read this book. For some of them, science can be so lonely that recognition of common struggles can be an inspiration. As Maria de Sousa once wrote to me:

I don’t know if Gerald Edelman ever gets depressed, or if Jim Watson or Francis Crick ever get depressed. But for the more ordinary of us, the strength that is needed to believe that what you believe in is worth pursuing is very great. And at the end of a Glasgow wet, windy week, it cries out. You have no idea how meaningful it is to have this project of ours going within myself. Meaningful in the sense that it gives meaning to all my moods, so I feel all that I am experiencing is not wasted.

Science at its creative core is inevitably a lonely business. However much scientists try to deny this and other subjective aspects of their work, one is ultimately driven back into the innermost recesses of the personality, and it is the struggles that take place there which shed light on the human predicament.

Perhaps only one person has been permitted to know Peter Medawar – one who has been essential to his career, success and survival, especially through the devastating illness that for sixteen years or more has hung over him. What Edna Healey has written of Charles and Emma Darwin in Wives of Fame could equally be written of Peter and Jean Medawar: ‘as he laboured through the dark, it was essential for him to know that she was there, steady and serene in the sunlight at the end of the tunnel.’