by Forrest E. Baird
If, as Descartes asserts, the mind and the body are different "substances," then what is their relationship? Descartes would say that the mind and the body interact. That is, the mind can cause changes in the body and the body can cause changes in the mind. But how can something non-material (the mind) cause a change in the body? If all material things are subject to the laws of motion, etc., then how can a thought cause a change in motion? If you ask most people this they will say it is a dumb question and then tell you something about the brain. But the brain is part of the body--a physical thing subject to physical laws--what does that have to do with the MIND? For example, if I raise my hand we can explain what happened in terms of muscles contracting, neurons "firing," chemical and electrical stimulations in various parts of the brain, etc., . . . but what does that have to do with the THOUGHT "I will raise my hand as an example"? Descartes explained it by referring to the pineal gland which (he said) is totally material at the top and becomes mental at the bottom. Right . . . no one else can make sense of that either. Actually it seems to reduce all mental phenomenon to physical phenomenon.
Descartes' view can be diagramed as follows:
That is, M1 (mental state one) causes a change in both M2 and B2 (bodily state two) and B1 (bodily state one) causes a change in both B2 and M2 and so on. But there are many problems here: 1) How can one event (say B2) be said to have two causes (one mental and one physical)? 2) As mentioned above, how can a thought cause an electrical/chemical change (unless the thought is ITSELF electrical/chemical--in which case it is not "mind", but only "body"? (Using the analogy of billiard balls, which Descartes does, how can a billiard ball be moved by something that is not itself physical?)
While Descartes' view can be easily critiqued, it is clearly the "common-sense" view. We generally all assume that the mind can change the cause-effect chain of the body's movements (as when we worry about something so much we get an ulcer) and that what is done to the body can change the mind (e.g., too much to drink). We probably want to drop the stuff about the Pineal Gland, but how DO we explain this?
This has got to be one of
the all-time goofy theories. In answer to how the body and mind interact, Geulincx
(a follower of Descartes) says "they don't!" The mind proceeds in
a cause-effect way and so does the body, but they have nothing to do with each
other! This can be diagrammed thus:
Now, it might take a second or two to see the oddity in this. What he is saying is that right now as your eyes are moving back and forth in front of this piece of paper that has nothing to do with your thinking about the body-mind problem. This morning as you were putting food into your mouth it had nothing to do with your tasting the food! Just think what would happen if you got a bit out of synch. It would be like those late night kung-fu movies where the mouths do not match the words. You would be moving your mouth and swallowing food while having all the mental images of reading about Descartes. Actually, I suppose you would never know that you were out of synch, would you (since "knowing" in this sense is a mental phenomenon only)? You might well ask how we could keep in perfect synch all through our how life!!! The answer, of course, is what all philosophers say when they hit a brick wall--"God does it." God insures that we keep in synch.
Bishop Berkeley (yes, the
city in California is named for him, but it is pronounced "Bark'-ley")
held this view. It solves the problem by simply denying that there is body--there
is only mind! This can be diagrammed thusly:
This, of course, seems absurd--obviously
there are bodies. But Berkeley should not be disposed of too quickly. As he
points out, we never actually encounter bodies as such. We only know our mental
impressions of them. (Yes, Berkeley is an empiricist.) Dr. Johnson said "I
refute Berkeley thus" and kicked a rock. But although that might be humorous,
it is irrelevant. Kicking a rock does not prove the rock is a body--it only
shows that my visual mental impressions coincide with my tactile mental impressions.
Much of this is to come in Hume.
One interesting side note here--does this mean that if no one is perceiving an object then the object ceases to exist? (Actually, Berkeley would say "what object--you mean my mental image?") If we all leave Cowles Auditorium, does it cease to exist? NO--why? Once again, the answer should be obvious--because GOD is still perceiving it! (Remember, he is BISHOP Berkeley!) Here is a little Berkeley limerick:
There was a young man who said "God,
I find it exceedingly odd
That this very tree
Should continue to be
When there is no one about in the quad."
The Answer:
"Young man, your question is odd.
I am always about in the quad.
And that's why this tree
Continues to be"
Signed by, yours faithfully, God.
This is the view of a number
of contemporary scientists in biology and psychology. I think it is fair to
put B.F. Skinner here. This view says there is no problem because we do not
really have minds--only brains. That is, everything is physical without any
mental substance. What we call mental is really just very complicated
physical (i.e., electrical/chemical) processes.
This can be diagrammed thus:
Among the many problems
with this theory is that it seems to remove free will. If everything I do and
"think" is simply the result of physical interactions, then it makes
no more sense to praise or blame me for what I do than to yell at the 8 ball
for going in the side pocket.
This is a tricky one supported
by several contemporary biologists. In essence it says that the mind is a "real
thing"--but only as a by-product of the complexity of the body. Accordingly,
the body can cause changes in the mind, but the mind cannot cause changes in
the body--though we think it does. For example:
Imagine that I slug you
very hard in the arm. You receive the blow (B1) which sets in motion a series
of bodily events (B2) leading ultimately to your secreting fluid from your eyes
(B3). However, B1 (getting hit) also caused M1--your feeling sad that I was
mean to you. You (mistakenly) think that M1 caused you to cry (B3)--that is,
that your sadness caused you to cry, but actually it was the complex series
of physical causes and effects (B2) that did it. (Your feeling sad also may
cause other mental events (M2) such as your thinking that you will get even,
etc.) You think it was your sadness that made you cry because every time you
have mental state M1 (sadness) it leads to bodily state B3 (crying). But correlation
does not equal cause and effect.
This theory does away with the problem of how the mind can "push" the body into a movement. But does this theory escape the charge of determinism that was raised against materialism? I do not think so--I think it is just fancy materialism.
All this leads to the eternal question--so what? What difference does it make anyway? Apart from questions about how to treat "mental illness" the most obvious application is to the question of free will vs. determinism. It makes an enormous difference in areas like our penal system. (If your bodily interactions--i.e., your environment--are the only things responsible for your bodily actions, then clearly a punitive penal system is nuts. You simply are not responsible for your actions.) It makes a difference in how I raise my kids, in how one chooses a mate, etc. Can you think of any other implications?