X-Message-Number: 4022
From:  (Thomas Donaldson)
Subject: Re: CryoNet #4010 - #4013
Date: Thu, 16 Mar 1995 22:43:56 -0800 (PST)



Re Turing machines:

My problem is not with the Turing thesis. My problem comes from the practical
fact that the speed of a computation often matters a great deal. That is why

parallel computers, neural nets, and other such devices exist. And in the sense 
that speed simply wasn't one of the factors which the Turing thesis took into
account, there are plenty of machines out there which are much more powerful
than a Turing machine. But it is a measure of power not in the same space,
but perpendicular to those which Turing considered.

To Mr. Clark:

I am sorry to sound condescending, but when you simply don't get simple observ-

ations you tempt the lower realms of my brain quite mightily ... most 
especiallybecause you quite obviously REFUSE to get it, not out of simple 
ignorance but
out of arrogance.

As you know very well, I am not denying the existence of symbols. I will note
however, that if you reread your original definition there was no mention
of any conventions. Furthermore, the structure of our brains did not come
about because of any convention. As for DNA, to speak of it as a "code" omits
the fact that it is not just a code: it is a physical chemical which has 
effects on other chemicals. Codes and conventions (and symbols too) have 
an arbitrary character; DNA does not. It is only when we try to understand
it that we think of it as a "code"... but without its special chemical 
characteristics it would do nothing at all.

To find order in the world is not the same as finding symbols in the world.
And for living creatures (or robots, or whatever ... even can openers) to
be designed or formed so that they make use of that order is not a matter
of symbols. True, if we are going to DISCUSS that order then we will use
symbols to do so, but our discussion is not the same as the order itself,
no matter how accurate it may be. And for me to say that we do not think
in symbols, but at a more basic level more like the operation of DNA than
like that of a computer, is not to say that we cannot USE symbols.

For what it is worth, I have spent a great deal of time studying the 
working of our brains. I find that operation far easier to understand on
the hypothesis that we are NOT working with symbols than if we suppose that
we are. I'll even say that the idea that we DO work with symbols, and 
that we should look to computers as models for how we actually work, has 
done far more to hold back our understanding of our brain than any other
pernicious idea ... more, in fact, than that of those people who may
ignorantly believe that we have a soul separate from the organization of
our individual brains. And anyone who looks for a computer in our brain
will not find it: but rather than decide simply that it isn't there,
proponents of such a view decide that it must be in hiding, somewhere,
and insist that without it we will not understand how our brains work.

This is NOT a claim that human brains or any brains work in a meaningless
way. DNA works quite well. So (mostly) do our brains, and there is a lot
of order in both DNA and our brains. Not only that, but our brains can 
accomplish some feats that computers still find hard, even though at the
same time they seem hopeless at tasks that a computer would finish in an
instant. They are not SIMPLE machines. But there are many complex machines
for which a claim that they operated with symbols would look like a total
absurdity.

Nor do I wish to denigrate computers. I've worked with them for a good
part of my own life. And I see great potential for what we will do with
them in the future. But intelligence in the sense that human beings have
it (whether that be good or bad) is not something that computers are
suitable for. If we want to copy it, we can do so with other kinds of 
machines.

I continue to think that this issue of "symbols" is key. If you wish you
can reformulate your definition. I am telling you that it badly needs
reformulation; and when I come up with a deliberately absurd case that
seems to fit it, I am giving you a counterexample. I hope you understand
that also.

So why is it that a tree which grows in the sunlight is not using 
symbols when its leaves make energy? And if the earthworm under the tree
is using primitive symbols, just what are they?

			Best and long long life, to all,

				Thomas Donaldson

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