[Hans Blom, 940510]
(Bill Powers (940509.0815 MDT))
So much to say, so little time. Just a few things, then.
You're quite right, of course, in terms of practical considerations
in the world as it is now. We always have to do the best we can with
what we know, and this always means we settle for less than full
understanding.
This may be a misreading of what I mean. I intended to say that full
understanding, both in theory and practice, _includes_ an awareness of and
a reckoning with our limitations. If not, the understanding is not full.
But should we then decide that since this is the best
we can do, we should focus on defending the way we do things instead
of trying to do better?
Two roads are open, as I tried to describe. The first is to conduct
experiments in order to be able to control better at a later time -- but
not now. The second is to act now -- and realize that afterwards you will
always be able to say that you could have done better if only you had
known better.
Since we live in a real-time world, acting "optimally" is to combine the
two options in the best possible way: do not hesitate for too long, and do
not act too stupidly. You and me, we are lucky in that the two aspects
coincide: doing experiments _is_ our favorite way of acting!
When you feel you must act on insufficient knowledge, then you must
act. This, however, doesn't mean that acting would necessarily be
better than not acting, unless you can count on having many chances
to succeed. If you don't bear the costs of your own failures, it's
easier to act under the policy that some action is better than no
action.
Here speaks a perfectionist. No action, I assure you, _is_ a form of
action. Let me try this on you, as an educator:
"Failures do not exist. You are learning. Learning means that you are
finding out how to do things that you do cannot do yet. Learning is
necessarily a "trial and error" process. Others may say that you make
mistakes, but I tell you that those "mistakes" are required in order
to truly learn. If you were an expert already, you would not make
mistakes. But neither would you learn. Experts have learned already,
they have made their "mistakes" already. They were not afraid to make
those errors; otherwise they would not be experts now. Do not say "I
made a mistake"; say "the outcome was different from what I intend-
ed". See the other side of the coin: making a mistake _is_ learning.
Be happy to make mistakes; it shows that you learn."
Why is it that learning receives so little emphasis in PCT? You always
stress the steady state, _being in control_. I am much more interested in
the dynamics, learning, becoming an expert. In our discussions, too. You
focus on how well we do, I on how much there is still to learn.
It's easy to label a scientist
who wants to improve knowledge as a "perfectionist," but that can
too easily turn into a simple defense of the status quo.
See how you emphasize the steady state situation?
In PCT we don't believe that it's necessary to percieve "the path to
the goal." The goal is not something that exists outside the
organism or in the future. It's a reference signal that specifies,
in present time, the desired end-state of perceptions, not the means
of achieving that state. Since the current difference between what
is being perceived and the state defined by the reference signal is
always calculable, it is possible to base present actions on that
error so the actions tend to make the error smaller.
Yes, that is what I meant to say. But there are situations where a
"current difference" is not available, as when you are lost in the woods
and don't know where you are. In such cases it is _not_ possible to base
present actions on a computable "error" so that subsequent actions make
that error smaller. The newspapers just reported about two boys who
escaped from an institution and hid in a cave. When their dead bodies were
finally found, it turned out that the cave was only some 200 by 600 feet
in size.
As to the relation between gambling and statistics, I fully agree.
Acting on the basis of statistical perceptions is always a gamble,
and as all gamblers do, one tends to remember the wins more vividly
than the losses.
Control theories that explicitly model an error term consider _any_ action
to be something of a gamble, because _some_ information is always lacking.
The model is, after all, an approximation. As to your remark that humans
tend to be optimists: I think that this is due to a deep-seated recogni-
tion that learning takes place, and that things that we cannot do today
can be done tomorrow. But then, this feeling can be exploited as well...
You may
justify controlling on the basis of statistical perceptions by
saying that this is all we have available, but that does not make
the quality of control any better.
Not better, _best_. Optimal, given the existing limitations.
I really don't see why these "other theories" don't fall under PCT.
Are they not concerned with making perceptions match some desired
state?
Yes and no. Most "other theories" recognize that you generally have many
simultaneous and possibly "conflicting" goals and that some "optimal"
compromise is required as to how to fulfill which goals by how much. You
want to stay home and read that book; you want to visit that friend; you
want to see that new movie; you want to make love with your lady; you want
to ... What are you going to do _now_?
I maintain that _every_ theory is a description only. An
'explanation' is a description in terms of already known
concepts. I see a theory as just a concise summary of
observations or experimental data.
Yes, I've heard that idea before. I think that idea is strongly
influenced by the statistical approach to nature. It doesn't
however, account for theories that propose underlying mechanisms
that are not directly observable. "Already known concepts" have to
come from somewhere; if one took your definition literally, there
could be no descriptions because there would be a grossly
insufficient supply of already known concepts and no way of
generating more. Where did the first "already known concept" come
from?
Our perceptual apparatus appears to abstract raw perceptions into concepts
like lines, corners, pitches and what have you. The concept "object" is
there, as Piaget has demonstrated. So are the concepts "surprise", "fear",
"love", "hate", amongst a great many other things. The basis is our physi-
ology.
Concepts have to be _invented_, and a very fruitful way of inventing
them is to propose models containing imaginary underlying
mechanisms.
More complex concepts are built upon the elementary ones. Some of these
invention processes have been described in the literature. Kekule is said
to have come upon the structure of the benzene ring thanks to a daydream
of a snake biting its tail. The results of this creative process of dream-
ing, phantasizing, imagination seem to be rather haphazard.
One counterexample can indeed destroy a theory, or at least demand
that it be revised. But too much is made of the other logical
conclusion, that no number of positive examples can prove the truth
of the theory. This is often used as a reason for accepting
confidence levels that are ridiculously low. Why should we accept p
< 0.05, when we might achieve confidence levels of p < 0.000001?
There is a qualitative difference between such confidence levels,
the difference between having an isolated fact and a fact that can
be used in extended reasoning with many other equally reliable
facts. It is the difference between superstition and science.
I see one bird, and it can fly. The same with a second, a third, a
twentieth. Can I now conclude that _all_ birds can fly? The same with a
hundredth, a tenthousandth, a millionth. Can I now? When can I? Much seems
to depend on where I do my observations and where I will need those
conclusions at a later time. When can I be certain about a generalization?
I do not see how a _qualitative_ difference arises; it's just a matter of
confidence -- or rather reliance.
There must be _some_ way to challenge a theory through experimental
testing, to make it meet the requirement of correctly predicting
outcomes. Without that, no theory should be let loose into the
world. Laboratory tests give us the opportunity to make the model
handle difficult cases and apparent exceptions, if it can.
That does not help. I gave the example of relativity theory versus quantum
theory. The lab proves both accurate to full experimental precision. They
were let loose into the world. Yet they are in conflict, i.e. they cannot
both be true; most likely neither is. The deep discrepancy between "truth"
and "useful tool" remains.
Why does this sound like a cop-out to me? If you have a collection
of phenomena, and a collection of different theories about them,
then no matter what happens you will be able to find one theory that
would have predicted the observation. Now, however, the problem of
prediction becomes the problem of knowing which theory to use. If
you can predict in advance that theory A should be used, and not B,
C, or D, then you have a theory that encompasses A, B, C, and D, and
should use it instead. If you have no such encompassing theory, then
you might as well flip a coin. Not knowing in advance which theory
to use, you remain completely unable to make a prediction.
The solution is called "expertise". I remember my math classes, where I
learned the tricks of differentiation thirty years ago. There was, much to
my surprise, no "theory" that described how, given a certain formula, to
derive its differential. There was just a bag of tricks, each one applic-
able under certain conditions. Initially I had a very bad match between
formula form and applicable method. But through practice I got better. Not
always the first method worked, but then the second or third did. You see
the same thing in many other circumstances. You have undoubtedly seen the
average housewife (excuse my political incorrectness) operate a too big
screwdriver on a too small screw. You, as an expert on screwdriving, imme-
diately, without thinking, pick the right screwdriver.
For the moment I see no possibility to translate this kind of expertise
into something that you might call "laws".
The only thing you have to gain from multiple theories about the
same phenomenon is that after the fact you can always claim to be
able to explain it. You just sort through the various theories to
see which one predicts what has already happened. If you have a
friend who has a theory that predicts just the opposite of yours in
every case, then you can team up, because together you have all the
possibilities covered.
Stories _after_ the fact are pretty useless, isn't it? After the fact, one
can defend anything. What do you really mean? That you'd rather talk about
your theories than use them?
I have this theory that under the right conditions, objects should
fall upward. While so far there has been little applicability for
this theory, if you ever hear of such a thing happening, be sure to
tell everyone that I knew it all along.
Let me play the educator again. Can you think of conditions where objects
_do_ fall upward? It isn't difficult 
Physics depends on the reproducibility of experiments, on
objects that do not change over time, and on classes of
identical objects.
No, it depends on understanding which variables are important and
which are not.
Is "important" an objective notion? Or do you mean the same thing as I do:
that the important things should reproduce (no two experiments ever repro-
duce in all aspects), that the important things should remain constant
over time (we probably need not keep track of the identities of the atoms
that constitute a body cell), and that identity is taken as that of the
important similarities (no two objects can be composed of the same indivi-
dual atoms)?
Nature has its own logic, which immediately becomes apparent when
you do experiments and try to predict what will happen.
Take care of what you say here! We had just established that people (phi-
losophers, the ones who have thought hard about these things) do not
agree. So when you say that nature's logic immediately becomes apparent,
it is apparent TO YOU. Someone else might see things differently. What
makes you so special?
What happens
happens, quite independently of what we think or hope will happen.
It's all perception. What happens may happen, but what I perceive of what
happens has a lot to do with what I pay attention to and what I expect. I
am sure that I will see different things -- or things differently.
I wasn't talking about philosophical agreements. I was talking about
making correct predictions of simple phenomena by actually doing
experiments, not just by talking.
I'm afraid that you do not take philosophers very seriously. They are,
after all, the ones who have paid the most attention to some of the things
most central to PCT: how come we do what we do, how come we know what we
know, what _can_ we know, etc. They're all modellers, in a way. And they
have been very aware of contradictions between what they think/say and
what they see -- helped by a centuries spanning debate that, although it
has not led to any definite truths, has debunked a great many capricious
theories.
If organisms behaved as randomly as you seem to
believe they do, life would be utter chaos. It is not. Organisms
behave in very regular ways most of the time.
That is what you perceive. You concentrate on control. I see a lot of
utter chaos, a lot of things that we would like to but cannot control.
Illness, death, unhappiness, loneliness. Very organic themes all. Con-
gratulations that you have everything under control. I must admit that I
do not.
If things don't naturally go the way you want, you
MAKE them go the way you want. That's the PCT model, and that's how
people work.
Oh, how I wish that were true!
I was not driven by an unfailing sense of certainty, but by the
knowledge that whatever happened, I could probably deal with it.
That is much more in the spirit of what I intended to say all along. It is
what I call being able to live with uncertainty.
The wise person
does not pretend that adequate control can be maintained under
conditions of great uncertainty. The proper thing to do when there
is a lot of noise is to change the environment until the noise
disappears. You don't go on driving a car with a loose steering
linkage. You fix it.
Ban war? Ban poverty? Ban discrimination? Illness? Death? I'm afraid that
we will have to live with our human limitations, now and forever more.
I would not say that many of our solutions to the big problems are
good enough. I think that most of them are lousy and getting worse.
You just said: "The proper thing to do when there is a lot of noise is to
change the environment until the noise disappears. You don't go on driving
a car with a loose steering linkage. You fix it." Please do. I would be
very, very grateful.
Greetings,
Hans