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 Can Machines Think?

The Turing Test Turing wants an answer to the question of whether or not it is possible that a machine could have intelligence Intelligence=the ability think that an ordinary adult human possesses

The Turing Test But he sees that this question could get hopelessly complicated very fast. So he proposes a different question: can a computer win at “The Imitation Game”? What Turing calls “The Imitation Game” is now called “The Turing Test.”

The Turing Test The Turing Test for Intelligence  There are three rooms. In A you have the tester. In B you have a person, and in C you have a computer.  The person in A can send messages via computer to B and C.  The person in A has a conversation with B and C for as long as she likes. The computer passes the test if the person in A cannot tell which room has the computer.

The Turing Test

Turing makes two claims about his test: 1. If something can pass the test, then it is intelligent. 2. It is possible that a computer could pass. From this it follows that machine intelligence is possible.

Language is Cool This test may seem really bad until one reflects on the sorts of capacities required to fool another person. First and foremost, the machine would have to be a competent language user.

Language is Cool This seems unremarkable to us, because we use language effortlessly all the time. However, being a competent language user requires that one have rather remarkable capacities.

Language is Cool In virtue of understanding a language using a finite number of words you can:  Use your finite mental capacities to understand a potential infinity of possible sentences  Understand totally novel expressions that no one has ever uttered in the history of the world:  “Jennifer Lawrence is eating a grilled cheese sandwich while riding a donkey on the top of the Sears Tower.”

Language is Cool If you could build a machine that could carry out a conversation it would have to be able to duplicate these capacities.

Language is Cool Turing thought that we would have computers passing his test relatively soon. But it turned out to be a lot more difficult than he thought it would be.

Language is Cool With all of our advances, there isn’t a computer around that can come close to passing the Turing test.

Language is Cool

These things are called CAPTCHA’s.  This is an acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart”  They typically rely on linguistic and perceptual capacities that computers have a hard time duplicating.

Objections to the Turing Test But just because no computer can pass, doesn’t mean one never will. But what if one does ? Does that mean that it is thinking?

The Chinese Room Searle presents a case that is supposed to show two things: 1. Passing the Turing Test is not sufficient to establish that something is thinking. 2. A computer could never think, even in principle.

The Chinese Room  There is a man in a room who is a native English speaker, and has never learned a word of Chinese.  In the room he has a pile of books that have a set of instructions written down on them.  The instructions say: “when you see….then write…” where the blanks are filled with Chinese symbols.

The Chinese Room  There is a slot through which a native Chinese speaker passes notes written in Chinese  The instructions in the books are such that no matter what the person writes down, if the man in the room follows them, what results is a sensible response written in Chinese

The Chinese Room

Does the man in the room understand Chinese?  Searle says no!  But the man does pass the Turing Test.  Passing the Turing Test does not establish that the thing being tested can even understand the words that are being used.

The Chinese Room More fundamentally, Searle thinks the case shows that a computer could never think.  This is because computers work by manipulating meaningless symbols (think 1’s and 0’s in binary)  That is exactly the kind of process that the man in the Chinese room is employing.  By manipulating symbols in this way, one will never get meaningful thought.