Textbook of AI

1912–1954, Mathematician, computer scientist, codebreaker

Also known as: Alan Mathison Turing, A. M. Turing

Alan Mathison Turing is the most consequential single figure in the foundations of computer science and artificial intelligence. His 1936 paper On Computable Numbers, with an Application to the Entscheidungsproblem introduced what we now call the Turing machine, an abstract device of unlimited tape, finite states and a read–write head, and proved that no algorithm can decide, in general, whether an arbitrary program halts. The paper simultaneously settled Hilbert's Entscheidungsproblem in the negative and gave the field its mathematical model of computation.

During the Second World War he led work at Bletchley Park on the German Enigma cipher, designing the electromechanical Bombe and contributing to the cryptanalytic methods that broke daily Enigma traffic. After the war he worked on the design of the Automatic Computing Engine (ACE) at the National Physical Laboratory and then on the Manchester Mark 1 at the University of Manchester. His 1948 internal report Intelligent Machinery anticipated almost every major theme of modern AI, search, learning, neural networks, training by reinforcement, but was unpublished in his lifetime.

The 1950 paper Computing Machinery and Intelligence in Mind opens with the question "Can machines think?" and substitutes for it an operational test, the imitation game, now universally called the Turing test. The paper sketches and rebuts nine standard objections, in the process laying the philosophical groundwork for AI as a research programme.

Turing's later work shifted to mathematical biology; his 1952 paper on the chemical basis of morphogenesis founded the modern field of pattern formation. Prosecuted in 1952 for homosexual acts, then criminal in the United Kingdom, he was sentenced to chemical castration; he died in 1954 of cyanide poisoning, ruled a suicide. He was posthumously pardoned by royal warrant in 2013, and the Turing Law of 2017 extended pardons to all men convicted under the same statute. The ACM's highest honour, the Turing Award, bears his name.