Alan Turing: The Enigma The Centenary Edition

by Andrew Hodges

  One person did, in contrast, investigate the capacity of language to separate the factual from the non-factual. But Wittgenstein’s methods were such that hardly anyone could ever be sure what he meant. Alan Turing’s approach was one that rode roughshod over Wittgenstein’s questions in a search for the simple truth at the centre – but it had the virtue that the picture he drew was clear and plain, something that could in principle be tried out. As for the integration of a theory of logical problems, a psychological theory which had led him to ‘the root of the problem’ in his own unhappiness, Tolstoy’s historical problem about the nature of individual action, Forster’s questions about individuals and class consciousness – all this would be too much for anyone to encompass, and it was certainly not the way in which he worked or thought. At Bletchley he had worked on the central logical problems, finding bold and simple solutions, while a vast human organisation sprouted around him; it had not been his role to pull the whole complexity together.

  He had clung to the simple amidst the distracting and frightening complexity of the world. Yet he was not a narrow man. Mrs Turing was right in saying, as she did, that he died while working on a dangerous experiment. It was the experiment called life – a subject largely inducing as much fear and embarrassment for the official scientific world as for her. He had not only thought freely, as best he could, but had eaten of two forbidden fruits, those of the world and of the flesh. They violently disagreed with each other, and in that disagreement lay the final unsolvable problem. In this sense his life belied his work, for it could not be contained by the discrete state machine. At every stage his life raised questions about the connection (or lack of it) between the mind and the body, thought and action, intelligence and operations, science and society, the individual and history. But these were questions on which, except in the most special ways, he went out without a word of comment. Russell and Forster, Shaw and Wiener and Blackett held forth on such subjects; Alan Turing played the humble pawn.

  He played the pawn, and ultimately he obeyed the rules. Alan Turing liked to consider himself as the heretic scientist, gloriously detached from the conventions of society in his quest for truth. But his heresy was directed only against the surviving fragments of a disintegrating religion, and the polite accommodations of the intellectual world. The hue and cry of philosophers seizing upon Gödel’s theorem in defence of human freedom, as though minds could be regarded as static, isolated, academic intelligences, was to the real servitudes of the twentieth century what Lowes Dickinson had called Cambridge: ‘a lovely backwater’. The mainstream was, in the 1920s, a case of68

  Jix and Churchill and Communists and Fascists and hideous hot alleys in towns, and politics, and that terrible thing called the ‘Empire’, for which everyone seems to be willing to sacrifice all life, all beauty, all that is worthwhile, and has it any worth at all? It’s a mere power engine.

  By the 1950s there was a new Empire, or rather two, each served by their respective scientists. Those great well-springs of the Years of the Modern – the liberation of the faculties of the individual, and the collective ownership of human resources – had been degraded into the liberalism of the Pentagon, and the socialism of the Kremlin. It was here that the important doctrines and heresies lay, not in the formalities of English class and Victorian religion.

  In the 1930s, King’s had held one central strength: Pigou and Keynes and Forster had not forgotten individual freedom when decrying the waste of laissez faire, and no more than Bertrand Russell did they fall for the glamour of the USSR. After Germany wrecked everything, and Hitler’s curse lay upon the victors and the survivors, that stream of independent thought no longer had the same significance. But there was a fleeting moment after the war, in the period before Britain became Orwell’s Airstrip One, when Forster could see the post-war world according to pre-war lights:69

  Owing to the political needs of the moment, the scientist occupies an abnormal position, which he tends to forget. He is subsidised by the terrified governments who need his aid, pampered and sheltered as long as he is obedient, and prosecuted under the Official Secrets Act when he has been naughty. All this separates him from ordinary men and women and makes him unfit to enter into their feelings. It is high time he came out of his ivory laboratory. We want him to plan for our bodies. We do not want him to plan for our minds…

  Alan Turing did come out of his ivory laboratory, and in some ways came out further than Forster did. Nor was he the Bernal whom Forster was attacking in this passage, who believed that scientists should rule the world. But he did not offer a word on what turned out not to be an ‘abnormal position’ but rather the real orthodoxy of the 1950s: a dependence upon colossal machines. His work, while being as near to pacifism as military work could be, still had the effect of increasing state dependence upon machinery not only beyond the control, but even completely outside the knowledge, of those who paid for it. In this process Alan Turing remained a cipher.

  In some ways the fears about scientists ‘planning for our minds’ were unjustified by events. Thus the plans for eradicating homosexuality by scientific means, like the claims of cybernetics, and like the other current dreams of truth drugs and lie detectors, were far too ambitious. They were certainly not a practical proposition in the Britain of the 1950s.* Although academic research and medical practice continued towards this goal, it never succeeded in attracting the full support of government. Instead the issue of how best to eliminate homosexuality was left as a juicy bone over which the bulldogs of moral conservatism could fight with the forces of technical progress. Meanwhile the growth of a new economy, in which advertising, travel, leisure and entertainment made sexuality ever more conscious an attraction, would undermine the conservative and the medical models alike. There would even be room for the notion of individual choice – an idea unheard in 1954. The state never adopted such great plans, scientific or otherwise, to control the behaviour of the whole population. There was an air of fantasy, ritual display, clashing of symbols, about the whipped-up ‘moral crisis’ of 1953-4. Instead the 1950s saw British government continue to relinquish much of the civilian economy to the fray of international business, tempered by the traditions of class, tribe, religion, elections and so forth. Thus Winston Churchill set the people free.

  This complex and contradictory future, rather than a 1930s vision of scientifically planned industry, or a 1950s fantasy of scientific mind-control, was the achievement of the new men. The old moral and social institutions, while persisting in form, would lose their absoluteness and all-embracing significance; even a bishop would soon be borrowing Carpenter’s phrase and preaching a ‘New Morality’. The lesson of the public schools, and of the no less grim training grounds of the lower orders, had been outdated in the 1920s and proved quite useless in crucial aspects of the Second World War, a fact learnt so reluctantly and so late. It was all the more pointless now that faith rested in the Wizard’s mechanical Deterrent, with Heath Robinson contraptions of attack and counter-attack taking warfare further and further from human hands and minds, playing an unstable game in which every player was losing all the time, and in which the British government, not to be left out, had taken the lead in a proliferation of implications.

  Alan Turing’s split state prefigured the pattern of growth that he did not choose to live to see: a civilisation where the singing and dancing and mating – and the thinking about numbers – would be offered to a wider class, but one built around, and working to provide, methods and machines of inconceivable danger. And in his very silence, he typified the mainstream of scientific collaboration in this policy. It would soon be clear that suspicion of scientists’ loyalties was just a passing difficulty; the arrogance of a few who thought they knew better than governments amounted to no more than the teething troubles in the establishment of the national security state. Who could see that in fact he had torn the curtain away and shown the fragile, erratic, embarrassing brain that lay behind the machine? For unlike Dorothy, h
e said not a word. He was no heretic: this was camouflage, although perhaps even he, who so rarely broke his promises, only just restrained himself at the end. Within his sphere he was the grand master; politically he was as he described himself in 1941: Churchill’s obedient servant.

  But he had never wanted to be the focus of the modern world’s contradictions. It had been his trouble all along that, although driven by the desire to do something, he wanted to remain ordinary, to be left alone in peace. These were incompatible goals, and there was no consistency in him. Only in his death did he finally behave truly as he had begun: the supreme individualist, shaking off society and acting so as to minimise its interference. While Nineteen Eighty-Four, which so impressed him, held references to science and intelligence which made a telling counterpoint to his own ideas, there was a level on which Orwell was saying something very similar to himself. Orwell would have cared little for the legacy of Bletchley Park, another development of the Ministry of Truth, nor for the computers being built by people utterly heedless of questions such as those of whose intelligence was to be mechanised, and what it was for. He would have loathed the King’s social culture, and the strand in Alan Turing that shared something with Edward Carpenter’s erotic short-cut to socialism. Yet there was an underlying common bond: that of the few cubic centimetres within the skull which were all that could ever be called one’s own, and which were to be defended at all costs against the ravages of the world. For all his contradictory elements, Orwell did not lose faith in the capacity of Oldspeak to convey the truth; and his dream of the plain-speaking Englishman was close to Alan Turing’s simple model of the mind – the vision of a science independent of human error.

  Bleak visionaries alike, they came from an England less lush than Cambridge, and breathed a cold mountain air from which fainter hearts drew back. They contradicted each other, for much of what Alan Turing wanted – both in science and sex – could hardly be described in Oldspeak, while George Orwell’s idea of truth required a connection of the mind with the world that the Turing machine did not have, and the Turing brain did not entirely want. Neither thinker could do justice to the whole, and nor could the whole complex person that was Alan Turing keep true to his simple ideas. Yet in reaching the niente of his Sinfonia Antartica, he kept as close to his vision as the exigencies of the world allowed. Never content with the academic problems of dots and brackets, he found a purer end than Winston Smith.

  With so few messages from the unseen mind to work on, his inner code remains unbroken. According to his imitation principle, it is quite meaningless to speculate upon his unspoken thoughts. Wovon man nicht sprechen kann, darüber muss man schweigen. But Alan Turing could not possess the philosopher’s detachment from life. It was, as the computer might put it, the unspeakable that left him speechless.

  *More precisely, it was predominantly the subject of male homosexuality that was coming into greater public prominence, just as the 1885 Act defined ‘gross indecency’ as a male crime. In the parallel period after World War I, much had been made of a supposed ‘Black Book’ compiled by the German secret service, containing names of thousands of ‘sexual perverts’, both men and women. This was one reason why in 1921 the Commons had voted to extend the 1885 Act to women. But the Lords rejected the proposal – believing that even to mention the crime would have the effect of giving women ideas. The fact that men received a conscious attention not accorded to women was, therefore, an aspect of male privilege-although perhaps Alan Turing would not have seen it in quite this way.

  * Once John Turing had asked his father what he hated most. ‘Humbug’, he replied without a moment’s hesitation.

  * Thus an exposition of this idea appeared in the 1931 American novel Strange Brother,9 one of the few accessible pre-war exceptions to the general silence: ‘You see the generative gland is made up, not only of the gland of reproduction, but of a gland which manufactures the chemicals that cause a man to be masculine in temperament, and a woman feminine.’

  ‘Both these chemicals are found in every human embryo. But if normal development does not take place, the feminine chemical may predominate in a male, or the masculine in a female. And we then get a man attracted by men, or a woman attracted by women.’

  ‘This, at least, is the most plausible theory that modern science has to offer. And our experiments on rats and guinea pigs bear out the theory We’ve proved that, aside from the function of reproduction, sex differences are chemical.’

  † Some of the results did not fit in, because the ‘normals’ sometimes had low ratios, and the gay men high ratios. But this was ingeniously explained: ‘Those few normal subjects may be latent homosexuals, whereas the homosexuals with the high ratios may not be of the true constitutional type.’

  ‡ In similar vein: ‘The growing importance of the sociological aspects of the subject makes urgent the continued investigation of the problem from a broad psychosomatic perspective.’

  * Thus Golla and Grey Walter were the two scientific colleagues thanked by W. Ross Ashby for reading the draft of his 1952 cybernetic book Design for a Brain.

  * The fact that he retained his OBE was itself an interesting detail of the case. The War Office would demand the return of medals from anyone guilty under the 1885 Act. The Foreign Office presumably, took a different view

  * At the Nuffield Foundation conference that Alan attended, P.B. Medawar had proposed a programme of experiments on male animals, injecting oestrogen in order to reveal the neuro-physiological mechanism through the consequent alteration in behaviour patterns. Rarely can a Fellow of the Royal Society have had the honour of sitting at the wrong end of such an experiment.

  † The work he was doing was on the application of sequential analysis to economics. Although he knew that Alan was interested in Bayesian statistics, he had no idea that Alan had independently invented sequential analysis in Hut 8.

  ‡ In a reform typical of the period, 1952 saw a change in American immigration policy from a legal definition of homosexuality (the breaking of a law), to a medical definition. The Immigration and Nationality Act of that year specified that ‘Aliens afflicted with psychopathic personality … shall be excludable from admission into the United States.’ In 1967 the Supreme Court confirmed that ‘the legislative history of the Act indicates beyond a shadow of doubt that the Congress intended the phrase “psychopathic personality” to include homosexuals.’ Strictly speaking, therefore, Alan Turing entered the prohibited category in 1952 irrespective of the trial; in practice, of course, the point was that he had been found out.

  * It may be that to avoid being sent to prison he had to give a promise that he would not repeat the ‘offence’, in addition to undertaking the hormone treatment. Lack of evidence prevents this point being settled. If he had so promised, he would have kept to it, but he would have been the first to observe that this said nothing about what he did abroad. For this reason his foreign holidays may have been all the more consciously a critical factor in his life after 1952.

  * Jung held that dreams had meanings, but did not believe that they could be deciphered according to some fixed scheme:28 ‘The interpretation of dreams and symbols demands intelligence. It cannot be turned into a mechanical system. … It demands … an increasing knowledge of the dreamer’s individuality…’

  * He did agree with Robin that one should not persist with efforts to gain the interest of a boy of less than fifteen or so. (Robin had attracted a good deal of attention as a boy, and a too enthusiastic admirer had had the effect of putting him off sex for a time.)

  † Even so, it was more easily legible than the message he once sent to David Champernowne which simply consisted of a piece of teleprinter tape. It had his friend spending hours on breaking the Baudot code.

  * E.B. Strauss, the Jungian psychoanalyst, whom Robin had known for a long time,

  † A reference to an incident in Robin’s boyhood, when the exiled Emperor of Abyssinia had resided near his home, and had invited Robin and his
mother to tea.

  ‡ There was a postscript to his letter to Robin: ‘Is the beginning of this letter whimsical or what?’ – a question he did not answer. Nor did Robin look for an answer: his own reply responded subtly to the news of a ‘crisis’ by recommending the novels of Denton Welch.

  * Robin’s interests were more uniformly distributed.

  † To be seeing a psychoanalyst, foreign and Jewish at that, was of course another source of stigma and certainly a drastic departure from his early background. It was typical of him that he should write in this open, nonchalant way. Nor was Lyn Newman a privileged confidante in the respect; thus Alan had also made friends with Michael Polanyi’s young son John, recognising in him a budding chemist, inviting him to dinner to talk about morphogenesis, and presenting him with an envelope labelled ‘scrapings from Alan Turing’s kitchen’. It contained samples from a mysterious growth on the wall which he optimistically imagined that John Polanyi could identify. While away in Canada, John had a letter from Alan32 ‘full of hope for the future and praise for his analyst’.

  * At Whitsun (24 May) he was due at Guildford, and on 30 May at Cambridge for Robin’s PhD oral examination, so his holiday was most likely in early June.

  * He had recently abandoned his motor-assisted bicycle and was using a borrowed one – a ladies’ bicycle, as it happened, for it made no difference to him.