Alan Turing: The Enigma

Alan Turing (1912-54) was a British mathematician who made history. His breaking of the German U-boat Enigma cipher in World War II ensured Allied-American control of the Atlantic. But Turing's vision went far beyond the desperate wartime struggle. Already in the 1930s he had defined the concept of the universal machine, which underpins the computer revolution. In 1945 he was a pioneer of electronic computer design. But Turing's true goal was the scientific understanding of the mind, brought out in the drama and wit of the famous "Turing test" for machine intelligence and in his prophecy for the twenty-first century.

Drawn in to the cockpit of world events and the forefront of technological innovation, Alan Turing was also an innocent and unpretentious gay man trying to live in a society that criminalized him. In 1952 he revealed his homosexuality and was forced to participate in a humiliating treatment program, and was ever after regarded as a security risk. His suicide in 1954 remains one of the many enigmas in an astonishing life story.

Alan Turing died in 1954, but the themes of his life epitomize the turn of the millennium. A pure mathematician from a tradition that prided itself on its impracticality, Turing laid the foundations for modern computer science, writes Andrew Hodges:

Alan had proved that there was no "miraculous machine" that could solve all mathematical problems, but in the process he had discovered something almost equally miraculous, the idea of a universal machine that could take over the work of any machine.

During World War II, Turing was the intellectual star of Bletchley Park, the secret British cryptography unit. His work cracking the German's Enigma machine code was, in many ways, the first triumph of computer science. And Turing died because his identity as a homosexual was incompatible with cold-war ideas of security, implemented with machines and remorseless logic: "It was his own invention, and it killed the goose that laid the golden eggs."

Andrew Hodges's remarkable insight weaves Turing's mathematical and computer work with his personal life to produce one of the best biographies of our time, and the basis of the Derek Jacobi movie Breaking the Code. Hodges has the mathematical knowledge to explain the intellectual significance of Turing's work, while never losing sight of the human and social picture:

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.

And Hodges admits what all biographers know, but few admit, about their subjects: "his inner code remains unbroken." Alan Turing is still an enigma. --Mary Ellen Curtin