The Turing situation

Alan Turing, just before World War II.

Alan Turing, a gay mathematician and computer pioneer who died in 1954, has been emerging from the shadows for some time now. There are many reasons for this. After decades of silence, the official secrecy imposed by Allied governments on his codebreaking work during World War II began to be lifted in the 1970s. His sexual orientation, almost unmentionable in his time, is now accepted as a matter of course. Technologists nowadays command public attention, even adulation. Vanity Fair’s annual New Establishment list routinely places tech-industry types in the company of media moguls and entertainment-industry stars; Steve Jobs’s demise occasioned an outpouring of public grief perhaps unmatched since the deaths of Princess Diana and John Lennon. Scientific and technical whizzes increasingly share in Western culture’s long-term fascination with geniuses. This is largely a residue of Romanticism, which glamorized rebellious creative titans such as Beethoven and Byron, but sometimes it shows, also or instead, our recognition of semi-mythic personages who fit the pattern of Philoctetes—outsiders who appear to us as both blessed and damaged, who are accepted by society because they’re needed but who remain marked as different, other. As one of those who suffered for his difference, Turing benefits as well from our ongoing efforts to rediscover and rehabilitate past victims of discrimination. He even serves the culture industry’s endless need for new subjects—that is, new products.

In recent years, Turing has been getting the celebrity treatment. President Obama, speaking to the British parliament in 2011, placed Turing in the company of Newton and Darwin. In 2009, British prime minister Gordon Brown issued an official government apology for Turing’s conviction, in 1952, on a charge of “gross indecency,” and in 2013 Turing was pardoned by the queen—a beneficence not yet extended to Oscar Wilde, who had been convicted under the same 1885 law, nor to tens of thousands of others. In 2012, the centenary of his birth, Turing was celebrated on a special postage stamp. (There were also many observances of a more specialized nature.) Last summer, the Pet Shop Boys premiered an oratorio about him in a BBC Proms concert, and a prestigious biographical film about him premiered last fall.

But if Alan Turing is now justly famous, it doesn’t follow that he was unfairly unknown before, and in truth he was never exactly obscure. He became a King’s College fellow in 1935, received the Order of the British Empire in 1946, and was elected a Fellow of the Royal Society in 1951; for a few years before his untimely death, in 1954, his name would have been recognized even by some members of the general public, from mentions in the press and Turing’s occasional appearances on BBC Third Programme radio broadcasts. At least two papers he published—“On Computable Numbers,” from 1936, and “Computing Machinery and Intelligence,” from 1950—achieved enormous influence among scholars during his lifetime and later became familiar to students in such fields as mathematical logic and computer science. Some aspects of his work became more widely known in the mid-70s, after the government-imposed secrecy that had surrounded the Ultra program since World War II began to lift. In 1978 (according to a London Review of Books account), Ian McEwan set out to write a play about Turing’s work at Bletchley Park; though he recast it as a television film and restructured it to focus on a woman, he kept the Turing-influenced title, and “The Imitation Game” was broadcast in 1980 on BBC1’s Play for Today series. When William Gibson deployed “Turing police” in the plot of Neuromancer (1984)—a force whose purpose was ironically not to promote but to prevent the emergence of super-intelligent machines—the joke was far from arcane to anyone knowledgeable about computers.

The problem was that, for a long time, no one knew the full story, saw the whole picture. As Alvy Ray Singer put it, in a recent survey of four books on Turing, the man himself “remained a cypher.” That changed almost overnight in 1983, when Andrew Hodges published the first edition of Alan Turing: The Enigma. That transformative book “told it all,” in Singer’s words, and is “still the Bible of Turing biography.” Other assessments agree in tracing the sea change in Turing’s situation to Hodges. An essay by Jonathan Swinton in a recent collection (quoted here) sums things up nicely:

“Propelled by [Hodges’s] brilliant biography…, the awareness of Turing as an iconic, field-defining figure passed from logicians and philosophers, through gay rights activists, applied mathematicians, cryptographers, artificial lifers, mainstream computer scientists, and into popular scientific culture, where he is now firmly established as a boffin of fiction, stage, and screen.”

A first-day cover issued by the Bletchley Park Post Office on February 23, 2012. Among the stamps, the one for Turing is at lower right, showing a Bombe codebreaking machine.

Last year’s film, an affecting drama on its own terms, is both inadequate and inaccurate in terms of its subject; anyone longing to know more about Turing’s life and work can do no better than to consult this account. In its 2014 edition, Hodges’s book contains 32 pages of prefatory material and 679 pages of text, including a final author’s note, plus a further 57 pages of notes and an index. It may appear daunting, but the book’s majestic—Tolstoyan? palatial?—scale is entirely justified. One finds here many figures in the carpet, many patterns in the numbers, many leitmotifs at play in the music. Like Tolstoy, Hodges captures a soul on its adventures within society; like a late-Romantic symphony, the book is vast, dense, highly organized, profoundly moving.

Themes arise and return, beginning, on the first page of the preface, with the timelessness of pure mathematics and G. H. Hardy’s remark of the prime numbers that they are so, independent of human affairs. Literary references abound: Walt Whitman extracts appear at the head of each chapter, and figures such as George Bernard Shaw, Samuel Butler, Edward Carpenter (a writer not previously known to me), George Orwell, and E. M. Forster repeatedly enter the discussion. A small constellation of metaphors appears throughout, the most prominent being that of the chess game from Lewis Carroll’s Through the Looking Glass. Concepts and totemic phrases from books that Turing had read, dating all the way back to a child’s introduction to science that he had been given at age 10 (which had implied that the brain is a machine), return as echoes throughout Hodges’s treatment. Binary oppositions, from the subtle (logical versus physical, theoretical versus practical) to the obvious (Victorian versus modern, gay versus straight), shape the book’s structure and much of its approach. Virtually everything that matters—whether David Hilbert’s so-called Entscheidungsproblem, which Turing had solved in the 30s (inventing along the way the concept of the computer), or the complex, charged topic of homosexuality in the 50s—is described with clarity and care, illuminated from many angles, and discussed knowledgeably, imaginatively, sensitively.

Hodges leaves only one issue unexplored: why the World War II codebreaking operation based at Bletchley Park—commonly known as the Ultra program, though Hodges rarely uses that term—was kept secret after the war. He writes only this: “The victorious western governments had a common interest, for obvious reasons, in concealing the fact that the world’s most sophisticated communication system had been mastered. No one questioned that this had to be so.” Nonetheless, others have questioned it since then. What’s more, Hodges is elsewhere not averse to discussing matters of state when they pertain to his subject, and this decision had enormous consequences for Turing. Official concern about his homosexuality depended greatly on the fact that he knew state secrets. What if, instead, these had not been secret?

One problem remains: Turing was all along hard to know. That’s why he’s labeled an enigma in the book’s subtitle; that’s why Hodges declares in the final paragraph of his main text, “With so few messages from the unseen mind to work on, [Turing’s] inner code remains unbroken.” How and why Turing died, though not the only unanswered question, is the greatest one. Hodges doesn’t directly challenge the inquest’s verdict of suicide but considers the possibility of an accident, a view favored by Turing’s mother; finding difficulties either way, he concludes that at one level “there was mystery; at another, a kind of inevitability.” Newer biographies argue for the accident scenario and even toy with the idea that he might’ve been murdered by the secret service, but they don’t, to my knowledge, offer any new evidence.

In his work on Hilbert’s Entscheidungsproblem, Turing had found that certain mathematical questions are necessarily undecidable. In a strange way, it’s fitting that the issue of Turing’s death remains, for now, undecidable too.