Home' Technology Review : July August 2007 Contents 64 ESSAY
TECHNOLOGY REVIEW /
ism but have done little to replace it with new ideas.
They ve showed us what we can t achieve (conscious
software intelligence) but not how we can create some-
thing less dramatic but nonetheless highly valuable:
unconscious software intelligence. Once AI has refo-
cused its e orts on the mechanisms (or algorithms)
of thought, it is bound to move forward again.
Until then, AI is lost in the woods.
What Is Consciousness?
In conscious thinking, you experience your thoughts.
Often they are accompanied by emotions or by imag-
ined or remembered images or other sensations. A
machine with a conscious (simulated) mind can feel
wonderful on the rst ne day of spring and grow
depressed as winter sets in. A machine that is capable
only of unconscious intelligence "reads" its thoughts
as if they were on cue cards. One card might say,
"There s a beautiful rose in front of you; it smells
sweet." If someone then asks this machine, "Seen any
good roses lately?" it can answer, "Yes, there s a ne
specimen right in front of me." But it has no sensation
of beauty or color or fragrance. It has no experiences
to back up the currency of its words. It has no inner
mental life and therefore no "I," no sense of self.
But if an arti cial mind can perform intellectually
just like a human, does consciousness matter? Is there
any practical, perceptible advantage to simulating a
An unconscious entity feels nothing, by de nition.
Suppose we ask such an entity some questions, and
its software returns correct answers.
"Ever felt friendship?" The machine says, "No."
"Love?" "No." "Hatred?" "No." "Bliss?" "No."
"Ever felt hungry or thirsty?" "Itchy, sweaty, tickled,
excited, conscience stricken?"
"Ever mourned?" "Ever rejoiced?"
No, no, no, no.
In theory, a conscious software mind might answer
"yes" to all these questions; it would be conscious in
the same sense you are (although its access to experi-
ence might be very di erent, and strictly limited).
So what s the di erence between a conscious and an
unconscious software intelligence? The potential human
presence that might exist in the simulated conscious
mind but could never exist in the unconscious one.
You could never communicate with an unconscious
intelligence as you do with a human---or trust or rely
on it. You would have no grounds for treating it as
a being toward which you have moral duties rather
than as a tool to be used as you like.
But would a simulated human presence have practi-
cal value? Try asking lonely people---and all the young,
old, sick, hurt, and unhappy people who get far less
attention than they need. A made-to-order human pres-
ence, even though arti cial, might be a godsend.
AI (I believe) won t ever produce one. But it can
still lead the way to great advances in computing.
An unconscious intelligence might be powerful. Alan
Turing, the great English mathematician who founded
AI, seemed to believe (sometimes) that consciousness
was not central to thought, simulated or otherwise.
He discussed consciousness in the celebrated 1950
paper in which he proposed what is now called the
"Turing test." The test is meant to determine whether
a computer is "intelligent," or "can think"---ter ms Tur-
ing used interchangeably. If a human "interrogator"
types questions, on any topic whatever, that are sent
to a computer in a back room, and the computer sends
back answers that are indistinguishable from a human
being s, then we have achieved AI, and our computer
is "intelligent": it "can think."
Does arti cial intelligence require (or imply the
existence of) arti cial consciousness? Turing was
cagey on these questions. But he did write,
I do not wish to give the impression that I think
there is no mystery about consciousness. There is,
for instance, something of a paradox connected
with any attempt to localise it. But I do not think
these mysteries necessarily need to be solved before
we can answer the question with which we are con-
cerned in this paper.
That is, can we build intelligent (or thinking) comput-
ers, and how can we tell if we have succeeded? Turing
seemed to assert that we can leave consciousness aside
for the moment while we attack simulated thought.
But AI has grown more ambitious since then.
Today, a substantial number of researchers believe
one day we will build conscious software minds. This
group includes such prominent thinkers as the inven-
tor and computer scientist Ray Kurzweil. In the fall
of 2006, Kurzweil and I argued the point at MIT, in a
debate sponsored by the John Templeton Foundation.
This piece builds, in part, on the case I made there.
A Digital Mind
The goal of cognitivist thinkers is to build an arti cial
mind out of software r unning on a digital computer.
Why does AI focus on digital computers exclu-
sively, ignoring other technologies? For one reason,
because computers seemed from the rst like "arti -
cial brains," and the rst AI programs of the 1950s---the
"Logic Theorist," the "Geometry Theorem-Proving
Links Archive May June 2007 September October 2007 Navigation Previous Page Next Page