[From Bill Powers (931206.0200 MST)]
I started a private correspondence on Martin Taylor's
930512.1230, but had some thoughts that might work better on the
net.
Mary pointed out the importance of this paragraph of Martin's:
Let's try a different tack. Early in my acquaintance with PCT,
I felt that the notion of "control system" was a metaphor for
something, but it was hard for me to see what it might be a
metaphor for. Gary, specifically, put me straight, that the
PCT "control systems" were exactly normal everyday engineering
control systems working in the real world. Now that made
everything make sense. One could bring to bear all the tools
that apply to control systems operating in the real world.
They really have to work. No fancy stuff. Just testing
against Boss Reality.
This was also my initial approach to control theory and behavior.
Everyday engineering, just checking out how living control
systems work in the real world. It took quite a few years for me
to see and begin to be able to say what is amiss in this normal
everyday engineering picture. I'm still searching for a good way
to say it, but the light began to dawn when I was working on BCP
and trying to get some definitions of the levels of control
worked out.
When you consider things like driving a car or pointing to a
target, the engineering model seems perfectly adequate. But as
you survey ALL the things that people control, you begin to
notice some anomalies: people control things that don't exist in
the environment in a way that an engineer can get hold of them.
In BCP I used the example of making lemonade. I like mine tart
and sweet, Mary likes it tart, period. What am I controlling when
I add lemon juice and sugar to make the lemonade taste right? If
you analyze the contents of the glass, you won't find any taste.
You might find correlates of what I'm controlling for, but you
won't find that single unified thing that I experience when I
take a sip. I'm controlling something that doesn't exist outside
me.
When I speak to a friend, I use a pleasant tone of voice. Where
is the pleasantness? Can you find it in the sound-waves that pass
from me to my friend? When the retirement checks come in each
month, I perceive a feeling of modest security that I gave some
effort to achieving. Where is that security -- is it floating in
the air in my house? Is it stored in my bank? When I open a door,
I create a space through which I can walk. Where is "through?"
You can search inside the doorframe forever, and you won't find
it there.
Once you begin to notice these physically nonexistent things you
perceive and control for, more and more of them show up. What,
exactly, is the "shape" of the person's face you are looking for?
What is the form of the "movement" with which you fill a spoon
with soup and convey it to your face? Where is the "sameness"
that you perceive between your checkbook balance and the bank's
balance (or the difference?). Where on the wallpaper is the
"pattern"? At what point in its trajectory, exactly, does a ball
"bounce"? Where, exactly, does the hill end and the valley begin?
What, exactly, is the relationship between where your car is in
its lane and what you actually see in the windshield? And where,
exactly, is that "relationship?"
These are not philosophical questions, but very practical ones,
because we can actually control all these kinds of experiences.
We can act so as to bring them into existence and maintain them
there; if we choose, we can alter them at will, by changing our
actions. Unless we pause to wonder, we are perfectly comfortable
in taking them as given aspects of the world that affects us and
on which we act. It's only when we try to make an engineering
model that controls those things that it beomes evident that
something is wrong. The engineer can control the measured
position of the car in its lane, but not the apparent position
that the driver experiences and controls.
The first temptation when thoughts like these crop up is to
divide the world into two parts: things that actually exist
outside of us, and things that we clearly make up through
perceptual interpretations: the objective aspects of the world,
and the subjective aspects. But that division can hold up only
for a while. The more carefully you look at the objective aspects
of the world, the clearer it becomes that there are none.
This is a concept that can't be communicated unless the listener
has independently discovered it, or takes time to search out
possible meanings for the words and is thus led to discover it.
It's all perception, the whole shebang, even the parts that seem
objective.
The point, before I stray too far off the subject, is that
control theory is really not about engineering or physics; it's
about a phenomenon of experience, the central aspect of our
relationship to the world. We act in order to affect what we
experience. We learn how to affect experience to make it come
closer to what we want it to be, and as long as that is what we
want, to keep it in that form. This is a simple and direct
observation about reality itself, which is the world of
experience, not the world of science or mathematics.
Science and mathematics are simply tools we have invented in our
attempts to describe order in the world of experience. But there
is nothing for those tools to work with unless we first notice
orderliness without their aid. PCT must first be grasped as a
real phenomenon of experience, _one's own_ experience. Reducing
it immediately to a mathematical representation and a physical
model, and then confining one's reasoning to the mathematics and
the model, is to turn away from the very phenomenon that PCT is
about. It is giving contemplation of the tools priority over
using them to explain phenomena.
PCT is not about controlling a plant in the external world. It is
about how we eat, walk, drive cars, find our way to a restaurant,
kiss our loved ones, argue with our colleagues, scratch an itch,
build our confidence, comb our hair, earn money. It's about
everything we do, every waking moment. That's the level where PCT
must first be understood, before there's any point in trying to
make a simplified idealized engineering or mathematical model of
control. It's a world view of behavior that can be checked
directly against experience, by anyone, without even drawing a
block diagram. When you grasp that world view, you then have
something to explain.
ยทยทยท
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Best,
Bill P.