Computing Machinery and Intelligence (1950)

Abstract Together with ‘On Computable Numbers’, ‘Computing Machinery and Intelligence’ forms Turing’s best-known work. This elegant and sometimes amusing essay was originally published in 1950 in the leading philosophy journal Mind. Turing’s friend Robin Gandy (like Turing a mathematical logician) said that ‘Computing Machinery and Intelligence’… was intended not so much as a penetrating contribution to philosophy but as propaganda. Turing thought the time had come for philosophers and mathematicians and scientists to take seriously the fact that computers were not merely calculating engines but were capable of behaviour which must be accounted as intelligent; he sought to persuade people that this was so. He wrote this paper—unlike his mathematical papers—quickly and with enjoyment. I can remember him reading aloud to me some of the passages— always with a smile, sometimes with a giggle. The quality and originality of ‘Computing Machinery and Intelligence’ have earned it a place among the classics of philosophy of mind. ‘Computing Machinery and Intelligence’ contains Turing’s principal exposition of the famous ‘imitation game’ or Turing test. The test first appeared, in a restricted form, in the closing paragraphs of ‘Intelligent Machinery’ (Chapter 10). Chapters 13 and 14, dating from 1951 and 1952 respectively, contain further discussion and amplification; unpublished until 1999, this important additional material throws new light on how the Turing test is to be understood. The imitation game involves three participants: a computer, a human interrogator, and a human ‘foil’. The interrogator attempts to determine, by asking questions of the other two participants, which of them is the computer. All communication is via keyboard and screen, or an equivalent arrangement (Turing suggested a teleprinter link). The interrogator may ask questions as penetrating and wide-ranging as he or she likes, and the computer is permitted to do everything possible to force a wrong identification. (So the computer might answer ‘No’ in response to ‘Are you a computer?’ and might follow a request to multiply one large number by another with a long pause and a plausibly incorrect answer.) The foil must help the interrogator to make a correct identification.