Alan Turing’s Imitation Game

Turing created one of the most brilliant thought experiments in the history of AI: the Imitation Game. Do people think like machines—or not? Alan Turing, alongside his first critic Ludwig Wittgenstein, initiated debates that still resonate today. In this article, let us focus solely on Turing’s landmark 1950 paper.

The paper opens with a simple question: “Can machines think?” This remains one of the central questions in philosophy—especially when trying to determine whether a robot with AI and some degree of embodiment could be intelligent or even conscious. Is our mind computational in some sense? Is consciousness something that can be replicated computationally, or is it inherently tied to biological organisms?

A Philosophical Starting Point for AI

There is a wide range of interpretations regarding the meaning of the Turing Test. Some scholars believe Turing was pessimistic about the possibility of a scientific account of intelligence and cognition. For instance, Stefan Rohde, a well-known proponent of enactivism, writes:

“The scenario developed by Alan Turing in his 1950 classic paper ‘Computing Machinery and Intelligence’ (Turing, 1950), which he called the ‘imitation game,’ expresses a deep pessimism towards the possibility to properly scientifically account for intelligence or cognition” (Rohde, p. 25).

He continues:

“The reality of how such systems are programmed and the kind of mistakes they make, however, quickly reveals that these agents do not actually think or have any grasp of the meaning of the symbol strings they produce. The cognitive achievement here is to be attributed to the programmer, not the programs” (Rohde, p. 26).

Other authors propose a different reading. Robert M. French (2012), for instance, suggests that Turing provided the “first operational definition of machine intelligence” (French, p. 164).

Today, many scientists regard the Turing Test as the first serious operational attempt to define machine intelligence, emphasizing that Turing’s criteria for thinking are purely behavioral. These interpretations often view human behavior in terms of mechanical configurations (Proudfoot, 2024). For Turing, the question “Can machines think?” becomes a purely empirical one—if the machine satisfies complex behavioral criteria, it counts as thinking.

However, some scholars push back. Saariluoma and Rauterberg (2015), for example, argue that “Turing was the first critic” of the computational theory of mind.

Turing’s Imitation Game Explained

Let’s look more closely at what Turing actually writes. He begins:

“Can machines think?” (Turing, p. 433)

Instead of defining “machine” and “think,” he proposes an experiment, the Imitation Game:

“It is played with three people, a man (A), a woman (B), and an interrogator (C) who may be of either sex. The interrogator stays in a room apart from the other two. The object of the game for the interrogator is to determine which of the other two is the man and which is the woman. He knows them by labels X and Y, and at the end of the game he says either ‘X is A and Y is B’ or ‘X is B and Y is A.’ The interrogator is allowed to put questions to A and B thus: C: Will X please tell me the length of his or her hair?” (Turing, p. 433)

Turing then asks the key question:

“What will happen when a machine takes the part of A in this game?” (Turing, p. 433)

The interrogator must then judge whether the answers came from a human or a machine.

Turing predicts:

“I believe that in about fifty years’ time it will be possible to program computers, with a storage capacity of about 10⁹, to make them play the imitation game so well that an average interrogator will not have more than 70 per cent chance of making the right identification after five minutes of questioning.
The original question, ‘Can machines think?’ I believe to be too meaningless to deserve discussion. Nevertheless, I believe that at the end of the century the use of words and general educated opinion will have altered so much that one will be able to speak of machines thinking without expecting to be contradicted.” (Turing, p. 438)

In conclusion, he introduces the idea of a learning machine:

“The idea of a learning machine may appear paradoxical to some readers. How can the rules of operation of the machine change? […] The rules are thus quite time-invariant. This is quite true. The explanation of the paradox is that the rules which get changed in the learning process are of a rather less pretentious kind, claiming only an ephemeral validity. The reader may draw a parallel with the Constitution of the United States” (Turing, p. 459)

On one hand, Turing’s approach can be seen as behaviorist, focusing on the functional and computational nature of machines—and possibly of humans. He does not discuss consciousness directly. But today, when technologies are increasingly “intelligent” and capable of goal-setting and adaptation, this paragraph can be very inspiring.

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Bibliography

French, R. M. (2012). Moving beyond the Turing Test. Communications of the ACM, 55(12), 74–77.

Proudfoot, D. (2024). Wittgenstein and Turing on AI: Myth versus reality. In Wittgenstein and Artificial Intelligence: Volume 1 – Mind and Language. Oxford University Press.

Rohde, S. (2010). Enaction, embodiment, evolutionary robotics: Simulation models for a post-cognitivist science of mind (Doctoral dissertation). University of Osnabrück.

Saariluoma, P., & Rauterberg, M. (2015). Was Turing a behaviorist? In Proceedings of the 17th International Conference on Artificial Intelligence (ICAI’15) (pp. 433–437). CSREA Press.

Turing, A. M. (1950). Computing machinery and intelligence. Mind, 59(236), 433–460.

Wittgenstein, L. (1958). The blue and brown books: Preliminary studies for the ‘Philosophical Investigations’. (2nd ed.). Basil Blackwell.

Image

Title: Alan Turing at Age 16
Author: Unknown
Year: 1928
Source: Wikimedia Commons
License: Public domain – free for use, no attribution required