February 13, 2007

I recently finished Andrew Hodges’s Alan Turing: the Enigma. The book is a definitive account of Turing’s life and work. In some places I found the level of detail overwhelming, but in others I admired the way Hodges uses his obviously extensive research to evoke the places and people in Turing’s life. The book is well worth reading for the perspective it gives on Turing, something which is absent from other, purely technical, accounts of his work.

Hodges portrays Turing as a man ahead of time, conceiving of the Turing machine as a thought experiment before the invention of the general purpose electronic computer, and inventing the Turing test when computing was in its infancy. Turing’s naivete was reflected in his refusal to accept what other people said could be done, but also in a lack of interest in the politics of his post-war work on computers and of his own homosexuality. A proto-geek, Turing was prickly, odd, and seemed to expect that the facts alone, when shown to people, would lead them to the same conclusions as he found.

Turing’s suicide is placed in the context of a move from regarding homosexuality as criminal to regarding it as a medical problem, and an increasing suspicion of homosexuals in classified government work. Hodges seems to conclude that Turing felt he had nowhere else to go.

You can’t help but wonder what else Turing might have accomplished had he not committed suicide. Greg Egan’s short, Oracle, is an entertaining what-if story, which also features a character very obviously based on C.S. Lewis. What if Turing had received help from a friend? It’s a pity that in reality there was no-one to lead him out of his cage.