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reason that the one is a translation, on another level of description, of the other. |
Sometimes "cause" will have its usual meaning: physical causality. Both types of |
causality-and perhaps some more-will have to be admitted in any explanation of mind, |
for we will have to admit causes that propagate both upwards and downwards in the |
Tangled Hierarchy of mentality, just as in the Central Dogmap. |
At the crux, then, of our understanding ourselves will come an understanding of |
the Tangled Hierarchy of levels inside our minds. My position is rather similar to the |
viewpoint put forth by the neuroscientist Roger Sperry in his excellent article "Mind, |
Brain, and Humanist Values", from which I quote a little here: |
In my own hypothetical brain model, conscious awareness does get representation |
as a very real causal agent and rates an important place in the causal sequence and |
chain of control in brain events, in which it appears as an active, operational |
force.... To put it very simply, it comes down to the issue of who pushes whom |
around in the population of causal forces that occupy the cranium. It is a matter, in |
other words, of straightening out the peck-order hierarchy among intracranial |
control agents. There exists within the cranium a whole world of diverse causal |
forces; what is more, there are forces within forces within forces, as in no other |
cubic half-foot of universe that we know. ... To make a long story short, if one |
keeps climbing upward in the chain of command within the brain, one finds at the |
very top those over-all organizational forces and dynamic properties of the large |
patterns of cerebral excitation that are correlated with mental states or psychic |
activity.... Near the apex of this command system in the brain ... we find ideas. Man |
over the chimpanzee has ideas and ideals. In the brain model proposed here, the |
causal potency of an idea, or an ideal, becomes just as real as that of a molecule, a |
cell, or a nerve impulse. Ideas cause ideas and help evolve new ideas. They interact |
with each other and with other mental forces in the same brain, in neighboring |
brains, and, thanks to global communication, in far distant, foreign brains. And they |
also interact with the external surroundings to produce in toto a burstwise advance |
in evolution that is far beyond anything to hit the evolutionary scene yet, including |
the emergence of the living cell.' |
There is a famous breach between two languages of discourse: the subjective |
language and the objective language. For instance, the "subjective" sensation of redness, |
and the "objective" wavelength of red light. To many people, these seem to be forever |
irreconcilable. I don't think so. No more than the two views of Escher's Drawing Hands |
are irreconcilable from "in the system", where the hands draw each other, and from |
outside, where Escher draws it all. The subjective feeling of redness comes from the |
vortex of self-perception in the brain; the objective wavelength is how you see things |
when you step back, outside of the system. Though no one of us will ever be able to step |
back far enough to see the "big picture", we shouldn't forget that it exists. We should |
remember that physical law is what makes it all happen-way, way down in neural nooks |
and crannies which are too remote for us to reach with our high-level introspective |
probes. |
The Self-Symbol and Free Will |
In Chapter XI I, it was suggested that what we call free will is a result of the interaction |
between the self-symbol (or subsystem), and the other symbols in the brain. If we take |
the idea that symbols are the high-level entities to |
which meanings should be attached, then we can' make a stab at explaining the |
relationship between symbols, the self-symbol, and free will. |
One way to gain some perspective on the free-will question is to replace it by |
what I believe is an equivalent question, but one which involves less loaded terms. |
Instead of asking, "Does system X have free will?" we ask, "Does system X make |
choices?" By carefully groping for what we really mean when we choose to describe a |
system-mechanical or biological-as being capable of making "choices", I think we can |
shed much light on free will it will be helpful to go over a few different systems which, |
under various circumstances, we might feel tempted to describe as "making choices". |
From these examples we can gain some perspective on what we really mean by the |
phrase. |
Let us take the following systems as paradigms: a marble rolling down a bumpy |
hill; a pocket calculator finding successive digits in the decimal expansion of the square |
root of 2; a sophisticated program which plays a mean game of chess; a robot in a T-maze |
(a maze with but a single fork, on one side of which there is a reward); and a human |
being confronting a complex dilemma. |
First, what about that marble rolling down a hill? Does it make choices? I think |
we would unanimously say that it doesn't, even though none of us could predict its path |
for even a very short distance. We feel that it couldn't have gone any other way than it |
did, and that it was just being shoved along by the relentless laws of nature. In our |
chunked mental physics, of course, we can visualize many different "possible" pathways |
for the marble, and we see it following only one of them in the real world. On some level |
of our minds, therefore, we can't help feeling the marble has "chosen" a single pathway |
out of those myriad mental ones; but on some other level of our minds, we have an |
instinctive understanding that the mental physics is only an aid in our internal modeling |
of the world, and that the mechanisms which make the real physical sequences of events |
happen do not require nature to go through an analogous process of first manufacturing |
variants in some hypothetical universe (the "brain of God") and then choosing between |
them. So we shall not bestow the designation "choice" upon this process-although we |
recognize that it is often pragmatically useful to use the word in cases like this, because |
of its evocative power. |
Now what about the calculator programmed to find the digits of the square root of |
2? What about the chess program? Here, we might say that we are just dealing with |
"fancy marbles", rolling down "fancy hills". In fact, the arguments for no choice-making |
here are, if anything, stronger than in the case of a marble. For if you attempt to repeat |
the marble experiment, you will undoubtedly witness a totally different pathway being |
traced down the hill, whereas if you rerun the square-root-of-2 program, you will get the |
same results time after time. The marble seems to "choose" a different path each time, no |
matter how accurately you try to reproduce the conditions of its original descent, whereas |
the program runs down precisely the same channels each time. |
Now in the case of fancy chess programs, there are various possibilities. |
If you play a game against certain programs, and then start a second game with the same |
moves as you made the first time, these programs will just move exactly as they did |
before, without any appearance of having learned anything or having any desire for |