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Date:         Tue, 29 Dec 1992 22:20:24 -0700
From:         "William T. Powers" <POWERS_W%FLC@VAXF.COLORADO.EDU>
Subject:      Misc catching up

[From Bill Powers (921229.2100)}

Eileen Prince (921229) --

I've just had a visit with some relatives who are into
"spiritual" pursuits, a la New Age stuff. I opened a couple of
the books they brought along. One was a guide to miracles,
written in pseudo King James English; the other was Jaguar Woman,
which seems to be about some magic worker or seer. I can't tell
you what they were really about because I didn't read more than a
paragraph or two from each, opened at random. I've seen that sort
of thing before, however, in the same circumstances, and have
been left speechless just as I was this time. What do you say to
someone who has adopted such system concepts? How can you have
any sort of substantive conversation when that is lurking in the
background?

The greatest mystery of the human mind, in my view, is this
phenomenon of Belief. Nazis are easy to deal with, because their
beliefs are threatening to our physical safety and we can flatly
reject them. But what about other belief systems, invented and
accepted apparently at random? Is the human mind just naturally
susceptible to any belief that comes around, no matter how
childish and full of holes? Is there something about our highest
levels of organization that demands some belief, any belief, to
fill the vacuum?

It seems to me that before we can have anything approaching
sanity on our planet, we must begin to understand how belief
systems get formed and how to keep them from overpowering people
-- how to leave a little freedom of belief, so that knowledge
about the WHOLE world of experience can play a part in forming
belief systems. I haven't the slightest idea of how to do that,
except by continuing to point out that different people believe
different things, a fact that ought to give anyone pause who is
convinced that his/her own belief system is the only right one.

Or is this a level at which we are all helpless, including me?

I second Tom Bourbon's encouragement for your writing an article
for Cosmopolitan.
-------------------------------------------------------------
Tom Bourbon (921228.1550  CST)--

RE: apology.

I've said worse to people when I've been mad. A friend is someone
you can call a stupid sunuvabitch without fearing that it's
goodbye forever. Say what you think; we're all grown up around
here.
-------------------------------------------------------------
Oded Maler (921229) --

>I agree and even more, only a small fraction of it will be
>relevant to anything... but which fraction? [of the abitrary
system will pertain to real system]
That's why we need the experimental approach, too. The weak point
of any abstract system is its premises, the things it assumes
about nature for the convenience of the argument, but which may
be false to fact. Pure mathematics doesn't have this problem,
although Godel rather spoiled the purity of the game. I interpret
his theorem to mean that all axiomatic systems, if they are not
to be vacuous, have to reside on outside support.

>Each community has its own system of rewards and
>encouragements, whether it is the church of established Science
>or the cult of enlightened PCTers.

I don't like that comment. What's wrong with established Science
is the establishment part, not the science part. I think we PCT
types go farther than most in sticking to the science and
avoiding becoming an establishment. It's only people who don't
ever do any experiments with real people who think that PCT is
just another belief system handed down from on high. The basis of
PCT is a set of easily reproducible phenomena that conventional
science has overlooked. To show that PCT doesn't follow from
these phenomena, you'd have to upset everything the physical
sciences have developed over the last 350 years or so. I don't
think that a system with such a strong base in phenomena deserves
the term "cult."

>About Sacks's book. I still recommend it (it is very easily
>read, especially for native English speakers). It has some
>cases of people who lost proprioperception and compenstated it
>thru visual feed-back loops, etc.

I've read that book, and others like it. It's another example of
the medical grab-bag of unassimilated facts. Interesting gee-whiz
facts, but what do they add up to? That whole field rests on
informal subjective characterizations of behavior without any
model to bring the facts into order. Until someone takes a model-
based approach to characterizing what is wrong with people who
have these difficulties, all we will get is more books like this
with more lists of unexplainable deficits.

I fully understand your problem with making a living. That does
get in the way. But there are always evenings and weekends, and
my God man, you're only 36!

>Your main problems, I think, will be to define the environment,
>(Boss reality, CEV etc.). The type of results these people
>usually have is of the form "given an environment obeying such
>and such restrictions (including stochastic ones), a controller
>defined like this and that will achieve performance such and
>such (e.g., mean error smaller than something). " Apparently
>you might want to prove some properties of your infamous
>hierarchical servo-loops aka HPCT, but what kind of properties
>exactly? Does the fact they they model living systems play some
>role? I think a first step in any direction is to state exactly
>what is your current dissatisfaction with the mathematical  >state-of-the-art
 of PCT. And please do it very slowly in small
>pieces, because I'm a very atypical pseudo-mathematicians.

When you recognize that the environment exists for a given person
only in the form of perceptions of it (through largely unknown
transforms at that), the problem becomes a little different. The
engineer takes the environment for granted: the variables he
perceives in it are Out There. The problem from the PCT
standpoint is not to achieve a particular result in the
environment, like perfectly browned toast, but to achieve a
particular perception that is a function of the environment but
not the same function for everyone -- like the shade of toast
that is deemed perfect. And it is to explain how such results can
be reproduced over and over even though different actions are
used each time.

I would like to know the mathematics behind perceiving forms and
shapes, which I call configurations and think I can see in many
sensory modalities, not just vision. The question is, how do you
get a signal that says "cube" when the object in question is
rotating and changing size and position? And how do you get a
signal that varies in magnitude as the presented shape begins to
depart from being a cube? The nearest I can get is "orthogonal
trajectories" as I mentioned in a recent post. But the kinds of
invariance we need sound more as if they require tensor algebra,
a subject that I know discouragingly little about, or
differential geometry, or some such beast. What kind of computing
network could extract such invariances? I don't think that
perceptrons have taken us very far toward an answer.

And that's only level 3 in my scheme. I think we're in the
position of early physics, where we can identify a lot more
phenomena, naturalistically, than our mathematical tools can
handle.

PCT does define the environment -- but it defines it as a set of
perceptions. Engineers usually assume that things like intensity,
color, form, relationship, sequence, and so on are properties of
the outside world. In HPCT we are attempting to explain, by
modeling, why the world appears that way to human beings -- and
at the same time, to point out that these things are human
perceptions. Physics does not explain why the world appears to us
in these categories. In fact, the world that physicists seem to
have uncovered has very little to do with such things.

I would like to know if there is any way, even in principle, to
establish a firm connection between the experienced world and the
world that exists independently of experience. That might be the
kind of problem a mathematician would enjoy -- unless Godel gets
in the way.

I suspect that Godel will get in the way. But even knowing that
the world an individual perceives has no unique relationships to
whatever lies outside would be important.
-------------------------------------------------------------  Rick Marken
 (921229) --

Your experiment with conflict is fundamental and new to our
repertoire. It is neat and beautiful. The fact that the model
reproduces the human behavior says that the real control systems
don't reorganize much until the task starts to become impossible.

Can you give us some numbers from the experiment?
-------------------------------------------------------------
Best to all,

Bill P.
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