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Turing's imitation game ("Can machines think?")
1950· Book or text· Knowledge, logic & science
Well documentedSolid records, texts or physical evidence.
Alan Turing's 1950 proposal to replace 'Can machines think?' with a test: can a machine pass for human in typed conversation?
See it on the Philosophy map →The idea
Idea: if a machine's typed answers cannot be told apart from a person's, we have as much reason to credit it with thinking as we have for other people. In 'Computing Machinery and Intelligence' (1950), Turing described an 'imitation game': a judge questions a hidden human and a hidden machine. He predicted that by about 2000, machines would fool average judges 30% of the time after five minutes, and answered nine objections. Main objection: Searle's Chinese Room (1980) argues imitation is not understanding.
Why it matters
It launched the philosophy of artificial intelligence and remains the best-known benchmark for machine intelligence, newly urgent in the age of chatbots.
Where it comes from
The 1950 paper, in the journal Mind, is widely reprinted. In a 2025 UC San Diego study, judges picked GPT-4.5, prompted to play a persona, as the human 73% of the time.
Still debated
Whether passing shows thinking or only skilled imitation is unresolved; many researchers now consider it a weak measure of intelligence.
Connections (3)
▸Turing's imitation game ("Can machines think?") launched Philosophy of artificial intelligenceWell documented
The connection
Turing's 1950 paper turned 'Can machines think?' into a testable question and answered nine objections, from theology to consciousness. It set the agenda: later philosophers either defended behavior as the mark of mind or, like Dreyfus and Searle, argued that something more is needed.
When and how
'Computing Machinery and Intelligence', published in the philosophy journal Mind in October 1950, while Turing was at the University of Manchester.
How we know
Its appearance in a philosophy journal and its list of objections make it the standard starting point; nearly every textbook in the field begins with it.
Debates and open questions
Whether Turing meant the test as a definition of thinking, or only as good evidence for it, is still argued.
▸Turing's imitation game ("Can machines think?") was challenged by Searle's Chinese roomWell documented
The connection
The Turing test says passing for human in conversation is enough to credit thinking. Searle built a case where the room passes such a test in Chinese, yet no one inside understands Chinese. If he is right, behavior alone cannot show understanding, and the test measures imitation, not mind.
When and how
Searle, at the University of California, Berkeley, wrote 'Minds, Brains, and Programs' (1980) in response to Roger Schank's Yale programs that answered questions about stories.
How we know
Searle's paper explicitly targets Schank's programs and 'strong AI'; commentators at once read it as an attack on the Turing test's behavioral standard.
Debates and open questions
Turing's defenders reply that we judge other humans by behavior too; whether Searle's intuition holds for systems vastly faster and larger is unresolved.
▸Turing's imitation game ("Can machines think?") gave a behavioural test for What is the mind?Mostly agreed
The connection
Instead of defining 'mind' or 'thinking', Turing proposed judging by behavior: if a machine converses as well as a person, deny it a mind only if you would deny one to people, whom we also judge by behavior. This shifted the old question of mind toward what a system does, not what it is made of.
When and how
Turing, at the University of Manchester, published the proposal in the philosophy journal Mind in October 1950.
How sure are we?
The paper is explicit, and it set off a long debate in philosophy of mind, feeding functionalism and provoking Searle's Chinese Room (1980).
Debates and open questions
Whether behavior can ever settle the question is the core dispute: critics say a system could pass while understanding or feeling nothing.