Alan Turing & the Imitation Game

alanturingHobyahs2smallThe Imitation Game is released in local theaters on Friday, so it seems a good time to discuss the philosophy of mind of the film's protagonist, Alan Turing.

The imitation game, or the Turing test, is a test in which a computer is pitted against a human in the task of convincing another human that it, the computer, is also a human.  The test is often construed as a means of gathering evidence that the computer is or is not intelligent, but this is a misrepresentation of Turing's actual position.  Turing is best understood as having maintained that being treated as intelligent, as having a mind, is constitutive of having a mind.  Passing the Turing test was not intended to merely indicate that the computer has a mind but rather to make it true that the computer has a mind.

Turing's test is an attempt to solve a centuries old philosophical puzzle: the problem of other minds.  I know that I have a mind because I have privileged, first-person access to it.  But I cannot know that you have a mind in the same way.  I could see that there are certain things that are true of me, e.g., I have a brain, I react in such-and-such a way to such-and-such a stimulus, etc., and infer that if those are true of others, then they too have a mind.  But to make that inference I must know that others are similar to me in the relevant respects, that what is associated with having a mind in my case is associated with having a mind generally.  I cannot know that on the basis of one case alone, i.e., my case, and I do not have access to any other cases.  It is puzzling, then, how we can come to know that other people have minds.

During much of the period of Turing's life, the 1920's and 30's in England and the 40's and 50's in the U.S., the philosophical movement of logical positivism (or logical empiricism) was dominant.  Logical positivism is really a family of positions, but they have in common the goal of providing a strict standard for the meaningfulness of claims, particularly philosophical claims.  Famously, many logical positivists rejected claims like "God exists", "God does not exist", "It is wrong to lie", and "It is not wrong to lie" as neither true nor false but rather meaningless because there is no possible way to verify or falsify such claims.

Since the claim that someone has a mind is neither provable nor falsifiable if we understand mind to be some unobservable entity, the British philosopher Gilbert Ryle argued that having a mind just is behaving as though you have a mind.  This would make the claim that one has a mind empirically verifiable since behavior is observable.  Bonus Points: Identify the most significant problem with this solution to the problem of other minds.

In this philosophical atmosphere, it makes perfect sense that Turing would take passing the imitation game to be one way to have a mind.  "Imitation game" is, however, a misnomer since the computer, if it passes the test, is not merely imitating something with a mind; it is something with a mind.  Turing wrote:

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.

Remember this the next time you're waiting for your computer to complete a function and you say to your friend, "It's thinking."

Turing, Alan. 1950. "Computing Machinery and Intelligence." Mind 59(236): 433-60.

Turing, Computing Machinery and Intelligence

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