Transcript Philosophy 1050: Introduction to Philosophy

Philosophy 1050:
Introduction to
Philosophy
Week 12: “Thinking Machines”:
Artificial Intelligence and
Human Minds
Mind and Intelligence:
Dualism vs. Physicalism
►
Last week we considered the
debate between the dualism
– according to which there is
a non-physical “mind” or
“soul” connected to the
physical brain – and
physicalism – according to
which there is no non-physical
mind and all of our behavior
and action can be explained
by the physical actions and
processes of the brain.
Artificial Intelligence:
The Question
► This
week, we’ll consider an important
related question. Could it ever be possible
for a machine – something made by
humans – to actually think, reason, hold
beliefs, have conscious experiences, etc.?
► And how could we tell if it could?
Blade Runner :
(Do Androids Dream of Electric Sheep?)
► The
year is 2019
► Deckard (Harrison Ford) is
a “Blade Runner” – an elite
cop trained to find and
hunt down human-like
androids or “replicants”
► Six replicants have escaped
from a prison colony and
are causing problems
Blade Runner:
The Voight-Kampf Test
►
►
In order to tell whether a subject is human or a replicant,
investigators use a complex test called the “voight-kampf”
test to evaluate their responses and reactions
Some of the newest generation of replicants have been
designed to give emotional responses and have even been
implanted with “false memories” so that they themselves do
not know they are not human.
Blade Runner
► If
you were Deckard and were
confronted with a tricky subject
who might be a Replicant,
what questions would you
want to ask him?
► How could you know for sure
whether your subject was
human or not? Could you
know for sure?
Turing and Computers
► Alan
Turing (1912-1954)
► During World War II, Turing’s
work on code-breaking was
instrumental in breaking the
“Enigma” code used by the
German and Japanese armies
► Because of this Turing has
been called the one
individual most responsible
for winning the war for the
allies
Turing and Computers
► Turing’s
ideas about
language and symbols
led him to develop the
idea of a “Turing
machine” or a
universal computing
machine
► The basic structure of
this machine is used
by every computer
that exists today
Turing’s Prediction (1950)
► “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 …”
Artificial Intelligence Since Turing
►
►
Since Turing wrote, artificial
intelligence has made great
strides forward. We now
have computers that can
identify faces, read music,
write poetry, and solve
problems that no human
could ever solve.
In 1997, IBM’s Deep Blue
defeated the world chess
champion, Gary Kasparov, in
a match of seven games.
Artificial Intelligence:
What are the Bounds?
► Since
1950, tasks once
thought possible only
for human beings have
again and again been
accomplished by
computers.
► Are there limits to this
progress? Is there
anything that humans
can do that computers
or machines never will
be able to?
Turing: The “Turing Test”
► Turing
considers the question: “Can
Computers Think?”
► But this question is unclear and difficult to
answer. Turing suggests replacing it with
another question, which he puts in the form
of an “imitation game” or “test”
The Turing Test
►A
judge is connected to
two subjects by teletype
machine
► One of the subjects is a
machine and the other is
a person: the judge
doesn’t know which is
which
► If the machine can fool
the judge into believing
it is a person, it is
actually thinking.
The Turing Test
► “I
believe that in about fifty years' time it will be
possible to programme computers, with a storage
capacity of about 109, to make them play the
imitation game so well that an average
interrogator will not have more than 70 per cent
chance of making the right identification after five
minutes of questioning.” (p. 4)
► Do we agree with Turing? If a computer can pass
the Turing test 70% of the time, is it actually
thinking?
The Turing Test:
Questions and Objections
► Is
there anything essential that a human
being can do that a computer could never
do? Why?
► Even if a computer can pass a Turing test,
how do we know it is really thinking as
opposed to imitating or simulating thought?
► If the Turing test is not a good test for
actual thinking, is there any better test?
Computer Thinking:
Objections
1) The Theological Objection:
“Thinking is a function of man’s immortal soul. God has
given an immortal soul to every man and woman, but
not to any other animal or to machines. Hence no
animal or machine can think.” (p. 5)
Response:
1) If God can create bodies and attach souls to them,
he could also attach souls to computers
2) Theological arguments are unsatisfactory for
establishing scientific conclusions
Computer Thinking:
Objections
2) The “Heads in the Sand” Objection:
“The consequences of machines thinking would be
too dreadful. Let’s hope and believe that they
cannot do so.” (p. 6)
Response: This is not really an argument at all,
but just an appeal for consolation.
Computer Thinking:
Objections
4) The Argument from Consciousness:
“No machine could feel (and not merely artificially signal ...)
pleasure at its successes, grief when its valves fuse, be
warmed by flattery, be made miserable by its mistakes, be
charmed by sex, be angry or depressed when it cannot get
what it wants.” (Geoffery Jefferson, 1949 (P. 6))
Response: If it is impossible to know that a machine is
really conscious judging from its responses, then it is
impossible to know whether any other person is really
conscious as well. If the Turing test could not show that a
computer is really thinking, then it is impossible for me to
show that anyone else (other than myself) is really
thinking.
Computer Thinking:
Objections
5) Arguments from Various Disabilities:
No computer could ever do X (where X is, e.g. “Be kind,
resourceful, beautiful, friendly, have initiative, have a sense
of humour, tell right from wrong, make mistakes, fall in
love, enjoy strawberries and cream, make some one fall in
love with it, learn from experience, use words properly, be
the subject of its own thought, have as much diversity of
behaviour as a man, do something really new.” (p. 8)
Response: Various, but all of these seem to be based on
a bad extrapolation from what we have seen before. Some
of the computers we have seen cannot do these things,
but that is no reason to think we could not eventually build
a computer that can.
Computer Thinking:
Objections
6) Lady Lovelace’s Objection:
Computers only do what they are programmed to
do, so it is impossible for a computer ever to learn
something new or do something unexpected
Response: Computers do “new” and surprising
things all the time. It is also easily possible for us
to set up a mechanism whereby a computer can
modify its own program, and thereby can be said
to have “learned.”
Computer Thinking:
Minds and Machines
► “The
‘skin-of-an-onion analogy is also helpful. In
considering the functions of the mind or brain we
find certain operations which we can explain in
purely mechanical terms. This we say does not
correspond to the real mind: it is a sort of skin
which we must strip off to find the real mind. But
then in what remains we find a further skin to be
stripped off, and so on. Proceeding in this way do
we ever come to the ‘real’ mind, or do we
eventually come to the skin which has nothing in
it? In the latter case the mind is mechanical.”
(Turing, p. 12)
Computer Thinking:
Summary
► Turing
suggested that computers could think and
he suggested the Turing test to determine whether
they can think.
► If we accept the test, it will be difficult to hold
onto a dualist or theological view of human
consciousness
► On the other hand, it is not obvious how to explain
consciousness or the possibility of a physical
organism giving rise to experience at all