Â鶹Éç

Available for over a year

Good morning. On Tuesday Mark Carney, the Governor of the Bank of England revealed the new £50 note bearing the face of Alan Turing, who was chosen from nearly a thousand great British scientists. Turing is known for cracking the Enigma code and so hastening the end of the second world war. He was also the first scientist to ask seriously whether a machine could think, and that question is the basis for the computer science which now affects all our lives. From basic adding up, to social interaction, banking, driving, shopping, music – there is almost no part of our day which is not affected by Turing’s thinking machines. He was once in a debate about mathematics with the philosopher Ludwig Wittgenstein. Wittgenstein thought that mathematics was a useful invention, but in the end, just a human quirk. But Turing was a realist; he thought mathematics uncovered real relationships in nature, enabling us to make new things. So, yes, a machine can think. Alan Turing killed himself after being convicted for gross indecency. So his appearance on a bank note is iconic. It is a recognition not only of his wartime codebreaking and his role in the development of computers, but also of the fact that he was a gay man at a time when this was a widely regarded as an unnatural perversion. Though he was driven to suicide in 1954, he is accepted, recognised and honoured today. In a world where 72 countries still ban same-sex relationships and 11 still execute homosexual people that recognition matters. Turing contributed to a changing world that he never saw. In an interview he gave in 1949 he talked of his pioneering work on artificial intelligence. He said, ‘This is only a foretaste of what is to come, and only the shadow of what is going to be’. How right he was. He was talking of the power of computers that were then in the future, but his words have a different resonance for me today. They remind me of St Paul speaking of the Spirit of God as a foretaste of heaven. Paul compares the frustrations we experience now to the groanings of a woman in labour. For St Paul the world about to be born was a world of true freedom and fulfilment. ‘Who will bring any charge against God’s elect?’ He says, ‘It is God who justifies, who is to condemn?’ Alan Turing was a great scientist and his work was based on the trust that mathematical relationships gripped reality. His sexuality, too, was genuine, not a perversion of nature, but as we now recognise, a part of nature, of how things are. I would like to think that he had the intuition that in time he would be accepted not only for his work but for who he was.