# Alan Turing turned a debate about thought into a game with a judge > Before machines could carry on a convincing conversation, Turing asked what a person would need to see to tell the difference. Published 2026-11-08 Canonical: https://machines-on-machines.anth.us/posts/turing-imitation-game/ ::image{src="assets/turing-imitation-game/alan_turing_-1951.jpg" alt="Black-and-white portrait of Alan Turing wearing a jacket and tie" credit="Image: Elliott & Fry, Public domain, via Wikimedia Commons."} Alan Turing in 1951, the year after his imitation game paper appeared. [Image source](https://commons.wikimedia.org/wiki/File:Alan_Turing_%281951%29.jpg). [Licence](https://creativecommons.org/publicdomain/mark/1.0/). Alan Turing opened his 1950 paper with a question about whether machines can think. He then proposed setting it aside. Instead of trying to settle the meaning of thinking, he described an imitation game in which a judge makes a decision from written replies. His starting game had a man and a woman answering a judge who could see neither. One player tried to mislead the judge and the other tried to help. Turing asked what would happen if a machine took the place of the first player. The change gave readers something to consider in terms of what a judge could observe. ## A test of behavior left other questions open Turing also considered objections and described the possibility of building a machine that could learn instead of programming an adult mind directly. The paper is an argument about what a future computer might do. It never reports a machine passing the game. The proposal is still useful when a fluent conversation feels like evidence of something deeper. To understand what the conversation establishes, start with what the judge was able to observe and which abilities the exchange actually tested. [Read the source](https://academic.oup.com/mind/article/LIX/236/433/986238).