[ The Physical Mind
| The Mind-Body Problem | Return to the Faith in Reason | Modern-Day Views ]
he roots of AI did not come from an obscure inventor pondering the
potential of machines, but rather in the minds of philosophers. While modern medical
technology has provided neuroscientists a detailed look into the physical structures
of the brain, the human mind is still the most mysterious object thus far. Other
fields like psychology
and cognitive
science have tried other means to determine the nature of intelligence without much
definitive success. Nevertheless, it is still important to know how the story
of AI unfolded in order to understand how it continues to grow and expand presently and
perhaps even where it is headed in the future.
One perspective on how people thought is the mechanistic view of
the human mind that governs strong AI belief.
It is believed that not only can intelligence be isolated in the confines of
the brain, but also the personality, consciousness, or the "self" people refer
themselves to can be understood from studying the physical processes governing the
functioning of the brain. In other words, to study how the brain works--essentially
the physical processes that govern its characteristics and function--would reveal how
people thought. So, the mechanistic view of the mind leads to the strong AI argument that
since the brain is governed by the physics of the universe, then it is a kind of
biological machine that can be explained and duplicated in an artificial machine.
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The Greek philosopher Plato(427-347 B.C.) was one of the first recorded
men to notice that there is a relationship between some aspects of thinking and
cause-and-effect mechanisms of a machine. From this spawned the great debates
on the concepts of intelligence, consciousness, and the idea of free-will versus man being
governed by predictable, natural, phenomena.
With great logical reasoning, Plato expressed his realization in Phaedo, The
Republic, and Theaetetus that there was a contradiction in the concept of consciousness and man's ability to choose his own
destiny. The mind is governed by natural laws which produces consciousness in
man while a machine, no matter how complex, is governed by those same laws but never
achieves consciousness. To explain such a paradox, Plato proposed an unchangeable,
soul-like existence that is directly related to consciousness--the ultimate reality of an
individual. This "soul" exists in the brain where it can interact
with the physical world on the level of "mechanics." Despite this
rationale, Plato still had a problem. If the soul/consciousness was not changeable,
then one could not learn and improve oneself from experience.
The contradiction in consciousness extends to the concept of free-will. Natural
laws are predictable; that is why the actions of machines are predictable. However,
man is governed by natural law which would make his thoughts and actions explainable and
predictable--in a sense, predetermined--which obviously goes against free-will. Even
if randomness was factored into man's behavior, it would eliminate the strong proponent
behind free-will which is the purpose of man. The only way to explain free-will,
thought Plato, was to attribute it to the "soul" or at least something that
transcended physical reality, but he felt that the mind was too ordered in some form to
use mysticism as an explanation.
The only way Plato could reconcile this contradiction was by declaring that the mind
had a dual nature--a paradox of a sorts. He drew upon this line of reasoning by
comparing it to the duality that exists in love--a human emotion both rooted in the
material world and the "ideal Form of transcendent emotion." Besides, there were
things in life which cannot be rationalized by logic alone even if they coexisted with
things that could be explained. For example, Plato inferred the existence of
irrational numbers like the square root of 2 which is in harmony with rational numbers. Though man can rationalize about
his own thoughts as far as he wants through scientific observation and reasoning, there
will always be a certain level of reality that cannot be rationalize, even with the power
of mathematics. That is when the only thing left for him to do is to accept what
cannot be explained as the consequences of creation.(Kurzweil 25-27)
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The Enlightenment(16th-17th century) was a period of great scientific progress and
social recognition thereof. It is at this time when philosophers renewed their
belief in the power of reason to understand the universe when they wanted to apply the
same logic used in science to philosophical notions.
Not surprisingly, most philosophers of those days were scientists themselves, like
René Descartes who worked in optics and partly developed modern analytic geometry.
Though he often did scientific research, it was more for the explanation to
prove his metaphysical beliefs. In Discourse de la Méthode, Descartes
reasoned how the mind can come from non-minds in what he called the "mind-body problem"
and rationalized that ultimately, the individual cannot be absolutely sure of anything's
existence except for his own; or in more succinct terms, "I think, therefore I
am."
The number of philosophers that dwelled on the mind-body problem all came to the
conclusion just as Plato did many years before: logic and scientific progress can explore
the mind and thinking, but there is a level of human existence that cannot be analyzed.
However, by that time, philosophers known as logic-positivists
had answered many of its metaphysical questions so the popularity of reason still existed.
The existential movement, on the other hand, began moving towards the the
embracing of the irrational side as a necessary part of the whole understanding of
reality.(Kurzweil 29)
The mind-body problem has obviously not be resolved, but there are a greater number of
thinkers involved in AI today who have asserted their opinions about the philosophical
debate. A few of them are surveyed here.
Professor of Cognitive Science and Computer Science Douglas Hofstadter clarifies the work
of AI by answering the question researchers commonly ask, "How finely will we need to
copy the brain to achieve AI?" His answer is simply how many features of human
intelligence do the researchers want to simulate. Hofstadter's weak AI position here
proposes that intelligence is achieved if people wanted a computer to play chess and
checkers like an intelligent person. However, broader aspects of intelligence like
language processing and pattern recognition require a finer-copying of the brain.(Hofstadter 572-573)
A philosopher at the University of California, Santa Cruz whose has interests in
artificial intelligence, David Chalmers'
suggestions that the nature of consciousness can be divided into "easy" and
"hard" problems. His simple problems are as follows:
Many of these problems are central in the development of AI and can be, in Chalmers'
opinion, studied by the underlying physical processes. The hard problem, on the
other hand, is studying how experience contributes to consciousness and intelligence
because experience is both information-processing--a logical phenomenon--and subjective.
(Chalmers, "Facing the Problem of Consciousness")
A discussion on AI is not complete without bringing in one of the forefathers of AI, Marvin Minsky. As the current Toshiba
Professor of Media Arts and Sciences and Professor of Electrical Engineering and Computer
Science at the Massachusetts Institute of Technology(MIT) who was a co-founder of the
university's AI Laboratory, Minsky has had a long history with AI. His explorations
in many aspects of AI like neural networks, music, and cognitive science led him to
constantly try out new approaches to AI. He was one of the people who came up with
the idea that the brain may process information in packets called frames and that intelligence may be a collective behavior of
simpler parts like neurons, as explained in The Society of Mind.
Finally, another important figure in AI is Roger C.
Schank who currently directs the Institute of the Learning Sciences at Northwestern
University. One of his deepest beliefs in AI is clearly stated:
