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Genius couldn't compute his own suicidal behaviour

Kim Vicente

Originally appeared in The Globe & Mail

The Man Who Knew Too Much is a densely argued biography about a boy genius who very quickly came to know far more than most of us can ever aspire to in a lifetime, and far less than almost any of us ever exhibit on a daily basis.

On the surface, Alan Turing — the renowned British computer scientist — appeared to live a charmed life. He was a heroic figure because of his landmark Jeffersonian contributions to both basic and applied science, all achieved during his 20s and 30s. On the fundamental research front, Turing wrote about the then highly controversial topic of "thinking machines," and discovered what is now known as the Turing Machine, the mathematical basis that still provides the theory for all modern digital computers.

And on the practical application front, Turing virtually single-handedly developed methods by which to break the ciphers used by the Nazi Enigma machine to send, transmit and receive top-secret military and diplomatic messages. This remarkable intellectual achievement made it possible for the Allied forces to secretly follow the Germans' moves, thereby playing a crucial role in winning the Second World War. Were it not for Turing's cryptanalytic contributions, the war would surely have lasted several years longer and could have been won by the Nazis.

But success can come with a price. Like all successful academics who reach out to the public, Turing was poisoned by venomous stalkers as well as petty colleagues. He was also a declared homosexual when such a "sin" was both abhorred and illegal. So, like Darwin, Turing chose simultaneously to take on the jealousy and competition of his academic contemporaries, as well as some of the darkest social taboos of his day. His research proposition that "machines can think" was overtly anti-religious, as was his sexual orientation, both weighty attitudes to adopt in mid-20th-century England.

Turing's undoing came in 1952, when he decided to pick up 19-year-old Arnold Murray outside the Regal Cinema in Manchester. This event led to a tortuous path of grief and then madness. Turing was arrested for gross indecency with another male, the same crime Oscar Wilde had been convicted of some 50 years before. He was convicted and sentenced to a "treatment" of estrogen injections, which was equivalent to chemical castration. On top of that, the injections had a series of humiliating side effects, causing Turing to become fat and to grow breasts. At the same time, Turing's security clearance was revoked and his ability to travel overseas was withdrawn, resulting in further emotional turmoil. Finally, at the age of 42, in 1954, Alan Turing committed suicide by eating a cyanide-laced apple, putting a halt to his meteoric rise as a mathematical genius.

Biographies can be written as core narratives with some context, or as contexts within which the life lived plays a smaller role. Successful U.S. novelist David Leavitt's well-researched book is written in the latter form. As a result, we get to read a great deal of mathematics (more than 60 pages out of less than 300 in total) as well as a great deal of history of mathematics, including the contributions and predilections of George Boole, Gottlob Frege, Alfred North Whitehead, Bertrand Russell, David Hilbert, Kurt Gödel, Alonzo Church, Godfrey Harold Hardy and John von Neumann. For many readers, this tack risks being too much detail and not enough narrative.

Nevertheless, we learn some deep lessons about Turing's persona from Leavitt's analysis. Much like the protagonist of The Curious Incident of the Dog in the Night-Time, Turing was notoriously literal-minded, which made him exceptionally difficult to get along with on an everyday basis. But he was a brilliant logician and mathematician professionally.

This penchant for saying precisely what he believed helps explain why he was a declared homosexual, even though he knew that the British Labouchere amendment of 1885 — it would remain law until 1967 — "criminalized unspecified 'acts of gross indecency' between adult men in public or private." Under these circumstances, "to be as open about one's homosexuality as Turing was either insane or revolutionary" — or perhaps, less generously, openly suicidal. We might be tempted by the latter interpretation, but Leavitt's insight into Turing's naive literal-mindedness convincingly rules out a deliberate will to do self-harm, and shows that his open homosexuality came instead from "an allergy to dishonesty" that naturally led to an active refusal to conceal sexual orientation and perhaps inevitably to a tragic ending.

Leavitt's book puts Turing's life into a light that is not only humane but also ruthless. It shows that flesh-and-blood human beings, like dispassionate logic, can suffer from contradictions that can lead to debilitating outcomes. The biography is a thought-provoking read for anyone deeply interested in the foundations of computer science, how code-breaking won the war, how homosexuality was viewed in puritanical Britain, and the unenviable price of fame, fortune and genius. There literally is such a thing as knowing too much.

Kim Vicente is professor of engineering at the University of Toronto. His latest book, The Human Factor, received the National Business Book Award and the Science in Society General Audience Book Award, and was short-listed for the Libris Non-fiction Book of the Year.