Alan Turing:
“Computing Machinery and
Intelligence”

•   “A person who makes calculations or computations; a calculator, a reckoner; spec.
a person employed to make calculations in an observatory, in surveying, etc. Now chiefly hist.
” [OED]
•   ENIAC : Electronic Numerical Integrator and
Computer (1946) was the world’s first electronic
“Turing complete” computer. [Wiki]

1985:
Kaypro: 64 KB RAM
2012:
Mac: 16 GB RAM

•   What is “thinking?”
–   Turing means more than mere calculating .
•   What kinds of things can think?
–   Human beings?
–   Non-human animals?
–   Computers?
•   How can we tell if something can think?
–   How do I know if you are a “thinking thing?”
–   How do I know that you are conscious?

•   The real question concerns how it is that we can tell if something is thinking.
•   Turing offers a “ functional definition ” of thinking:
–   A thing thinks if it meets the same behavioral criteria as do the paradigm cases of thinking things,
•   i.e., if it acts (in the relevant ways) the same way that human beings act.

•   Played with 3 people “a man (A), a woman
(B), and an interrogator (C).”
•   “The interrogator stays in a room apart from the other two.”
•   The interrogator asks questions and tries to determine, from the answers, which answerer is the man and which is the woman.

•   Instead of asking whether or not a computer can “think,”
–   How could we measure that?
•   Ask instead whether or not a computer could successfully play the “imitation game,” and fool a questioner trying to figure out which answers come from a human.
–   This is at least something we can measure.

Can digital computers “be made to play satisfactorily the part of A in the imitation game?”
•   “ The new problem has the advantage of drawing a fairly sharp line between the physical and the intellectual capacities of a man.”
–   i.e., by looking at the answers provided (rather than what the ‘answerer’ looks like, etc.), it focuses on what is “essential” to thinking.

•   “ I believe that … it will be possible to program computers, with a storage capacity of 10 9 [i.e.,
10 gigabytes], to make them play the imitation game so well that an average interrogator will not have more than 70% chance of making the right identification after five minutes of questioning.”

•   Any computer (hardware plus software plus data) that can successfully play the imitation game
–   i.e., one that can provide answers to our questions to it that we can’t distinguish from the answers provided by a human being—
•   …thinks !
–   I have no more reason to deny that it “is conscious” or “has inner states” than I do to deny that you do.

•   The Imitation Game gives us a functional definition
(a behavioral criterion) for whether or not something can think.
•   Since we can’t “look inside other people’s minds” this is the best criterion we can get.
•   If computers can successfully play the imitation game, then they meet the behavioral criterion, and so
(we would have no reason to deny that) they think .
–   So, if it quacks like a duck, it’s a duck !

•   1) Only things which are conscious
(i.e., that have conscious mental states) can think.
•   2) Computers are not conscious (i.e., do not have conscious mental states).
•   3) Therefore, computers cannot think.

•   But how do we know that computers aren’t conscious?
–   Isn’t this essentially the same question we are discussing …
•   … i.e., whether or not computers can “think?”
•   The objection begs the question :
–   The real question is whether or not computers can be conscious. The objection just assumes that they cannot.
•   How can we tell if other human beings are conscious
—that other human beings can “think?”

•   I am pretty sure that I think!
–   I am directly aware of my own thoughts.
•   How can I tell if someone (something) else thinks?
–   If I need to be directly aware of their thoughts, then I can’t know anyone thinks except me.
–   If I don’t need to be directly aware of their thoughts, I must rely on observable criteria.
The “Turing Test” provides such criteria.

•   I can’t “see” anyone’s conscious mental states but my own.
•   All I can “see” is their behavior (how they answer questions, etc.).
•   If I judge that other people think, simply on the basis of observing their behavior, without directly seeing their conscious mental states, then I must reach the same conclusion about computers.
•   Alternately put: If I deny that computers can think because I can’t see their “inner states,” then I will have to deny that other humans can think, for the same reason. This is solipsism .

•   The criteria we in fact use to attribute thinking
(consciousness) to other human beings are behavioral.
–   These criteria concern linguistic behavior—how a think talks , not what it looks like .
•   If these are the criteria I use with other human beings, it would be inconsistent to demand some “higher standard” of computers.
•   So, if a computer could meet the same standards of linguistic behavior as do other human beings (i.e., if it could successfully play the imitation game), we must, on pain of inconsistency, claim that it “ thinks, ” i.e., that it is “conscious.”

•   How do we tell that some other being (human or non-human) “thinks” or is conscious?
–   Is it really by observing their behavior?
•   Aren’t infants/pets aware of their parents/owners emotions (mental states)?
–   Are they inferring this on the basis of the linguistic behavior they observe?
•   Did you have to learn that others are conscious?