Thanks to Ed Nixon for a link to an interesting article by philosopher
John Searle, arguing against Ray Kurzweil’s contention that computers
will soon be smarter than people.
The strong part of Searle’s article is the argument that “syntax is not
semantics” — a computer that can calculate chess moves based on
pre-defined algorithms does not actually understand chess. Searle argues
successfully that Deep Blue is unintelligent in the same way that a
pocket calculator is unintelligent; it is simply manipulating symbols,
just as a human who speaks Chinese phrases using a transliteration is
manipulating symbols but does not understand Chinese.
Searle is right that Deep Blue is very far from being conscious. The
fact that a computer can beat a human at chess means about as much as
the fact that an automobile can move faster than a runner. Humans
designed the automobile; and human programmers chose the heuristics that
drive Deep Blue’s decisions.
Searle is less successful with the argument that a computer cannot have
intelligence, since a computer contains a mere model of intelligent
processes; and models are different from the physical things that they
represent.
Searle acknowledges that human intelligence is an emergent property of
neurons firing in the brain. This means, though, that intelligence is
based on circuitry, a pattern of information. Similarly, scientists are
gradually deciphering the informational patterns of genes and gene
expression. The lines between information and reality are not so clear
cut; it may be possible to develop living, even intelligent patterns in
some other medium.
Human intelligence probably has subtle dependencies on the biochemical
nature of the brain and the organism. Tom Ray makes this point
beautifully. But it does not follow that the only possible kind of
intelligence requires a body; it certainly does not follow that theonly
kind of intelligence requires this sort of body.
It may be theoretically possible for intelligence to develop in some
other medium. But despite Kurzweil’s optimism, there is little evidence
that we have any idea how to do this. Searle is right that just because
we can program computers to play chess does not mean we are anywhere
near creating computers with conscious minds.