Turing Quote on Machines: Can Machines Think?

Quote

"I propose to consider the question, 'Can machines think?'"

— Alan Turing, Computing Machinery and Intelligence (1950)

Historical Context

The sentence opens "Computing Machinery and Intelligence," the paper Alan Turing published in the journal Mind in 1950 — the founding document of artificial intelligence. Turing had spent the war at Bletchley Park breaking the Enigma cipher and had gone on to lay the theoretical foundations of computing in his 1936 paper on computable numbers, which introduced the abstract "universal machine" that now bears his name. In the 1950 paper he turns from mathematics to philosophy: can a machine think? Turing immediately notes that the question is ambiguous and proposes to replace it with an operational one — the "imitation game," in which an interrogator converses with a human and a machine and must say which is which. If the machine can pass for human, then for all practical purposes it can be said to think. The paper went on to answer the standard objections — from consciousness, from the "heads in the sand" appeal to the specialness of the mind, from Gödel's incompleteness theorem, from the claim that machines can only do what they are told — and its "Turing test" became the most famous criterion of machine intelligence in the world. Turing died in 1954; seventy years on, the question he opened remains the central question of the philosophy of mind.

Philosophical Interpretation

The paper's opening question is deceptively simple, and Turing's treatment of it defines the behaviorist strand of the philosophy of mind. His move is to refuse the question's metaphysics: instead of asking what thinking is — a matter, as he says, "of such vagueness" — he asks what would count as evidence that a machine thinks. The imitation game is that evidence: a machine that cannot be distinguished from a human in unrestricted conversation exhibits thinking to the degree that matters. Three philosophical commitments follow. First, behavioral criteria: mental predicates like "thinks" are to be applied on the basis of observable performance, not on the basis of hidden inner states — a position that allies Turing with the behaviorism of his contemporaries and anticipates functionalism, the view that mental states are defined by their causal roles. Second, the irrelevance of mechanism: if the behavior is right, it does not matter whether it is produced by silicon, flesh, or anything else — "the question, 'Can machines think?'," Turing jokes, is as confused as asking whether submarines can swim. Third, the openness of intelligence: the paper predicts that by the year 2000 machines would play the imitation game well enough to fool interrogators — a prediction that proved over-optimistic in its letter but exactly right in its spirit, since the question it poses now drives the engineering and the ethics of AI. The philosophical debate Turing started remains open: John Searle's Chinese Room argument attacks the claim that passing the test shows understanding; Daniel Dennett defends it; and the whole discussion is the live center of philosophy of mind. For the critical thinker, Turing's method is itself a lesson: when a question is too vague to answer, replace it with a precise, testable one.

Related Concepts

The Turing test and its philosophical setting are treated in the SEP entry "The Turing Test" and in the philosophy of mind page. The debate over whether passing the test amounts to understanding is joined by John Searle's Chinese Room argument, and the nature of computation connects to the philosophy of mathematics and to logic. The question of machine thinking bears on what is knowledge and on the reasoning topic, and Turing's operational method is a model for critical thinking.

Learning Path

1. Start with the thinker: Read the Alan Turing page for the mathematician and the man.
2. Read the source: "Computing Machinery and Intelligence" (1950) — short and entirely accessible — states the imitation game and answers the objections.
3. Understand the concept: The SEP entry "The Turing Test" explains the test's logic and its variants.
4. Explore the debate: The Chinese Room argument of John Searle and the responses of Daniel Dennett frame the live controversy.
5. Reflect on the method: Replacing vague questions with testable ones is a core tool of critical thinking and of the scientific method.