dynamicists -- wrong, wrong, wrong

CSGnet Archive CSG1993
1

[From Rick Marken (931130.1900)]

Martin Taylor (921130 11:30) --

Rick, I was trying to explain why a dynamicist might not be interested in
control or purpose, and yet have a valid way of looking at the world.

Why would anyone need this explained? You don't have to explain why
Isaac Newton wasn't interested in control or purpose, do you, and he
sure had a valid way of looking at the world. I'd imagine that the
only people who are interested in control or purpose are the people
who are interested in control or purpose. The validity of their view
of the world (whether they are interested in control or not) is quite
a separate issue.

You respond from the position that your way of looking at the world is
the only valid one, and if a person does not see everything as based on
control and purpose their view is wrong, wrong, wrong. I suggest that
their purpose is theirs, not yours.

I'm sure I'm as biased as the next person -- maybe more -- but I sure
don't expect people to "see everything as based on control and purpose".
Control (also called purpose) IS A PHENOMENON!!!! It doesn't explain
anything. Control (purpose) is something TO BE EXPLAINED. The dynamicists
of whom you speak (the Kelso, Turvey, Kugler, et al type) are trying
to explain control (the phenomenon) using models that DON'T CONTROL.
That's as bad as using a model that controls to explain phenomena (like
the motion of a pendulum) that DON'T INVOLVE CONTROL. The dynamicists
are wrong, wrong, wrong because they are trying to explain control
phenomena with non-controlling models. If their purpose were NOT to
explain control phenomena, then they would be physicists; they would
apply their models appropriately to non-control phenomena and I
would have (almost) nothing to be obnoxious about. But, as it turns out,
I am right (this time) and you (and the dynamicists) are wrong.

I said:

The basic phenomena of purpose (control) are produced by any
stable, closed negative feedback system; this was the point of my "Blind
Men and Elephant" paper.

Martin replies:

Well, I don't mind if you give every vortex in a stream "purpose," but I
do think that this usage goes a bit beyond the normal bounds of the term.

Perhaps I should have said "high gain" -- that would eliminate the vortex.
But you missed the point anyway. You had said that purpose only arises from
a negative feedback systems with a VARIABLE REFERENCE. This is demonstrably
wrong. I can write a model of a control system with no explicit
reference signal -- and it still controls (exhibits purpose).

So that makes two wrongs (wrong, wrong) for you, 0 for me (so far).

You said:

Perception is the way purpose is achieved

I said:

How about: Perception (the state of a perceptual variable) is the
purpose that is achieved by a control system.

You reply:

Oh, come now. The difference between the perception and the reference
is the degree to which the purpose is achieved. The reference level is
the purpose, surely.

I'm happy to call the reference level the purpose. But that just reveals your
statement "Perception is the way purpose is achieved" to be even more
profoundly wrong. It says that perception somehow guides itself toward
the reference level. Your belief in information in perception is showing
again. You failed to step out on Tom's ledge and trust that perception
is NOT the guide; it is not responsible for the fact that outputs keep
perception at (or very near) the reference level. Perception is precisely
(and demonstrably) NOT the way purpose is achieved.The closed negative
feedback control loop is the way purpose is achieved. Perception is
what is controlled.

So that makes three wrongs for you (wrong, wrong, wrong -- just what you
you expected me to say), still zero wrong for me. And, as everyone knows,
three wrongs don't make a wright.

Try rereading the quoted sentence.

I only re-read the Bible, Shakespeare, Dr. Seuss and Bill Powers.

It was about
why we should not necessarily expect someone interested in dynamics
issues to be concerned about PCT, and why we do not have grounds for
criticizing their lack of interest.

If they were only interested in dynamics issues then we wouldn't give
a damn about their lack of interest in PCT. But they are applying
there non-controlling dynamic models to phenomena that clearly involve
control. That's why I criticize their lack of interest in PCT. If
the dynamicists are NOT trying to explain purpose (control) then
1) why do they say they are (Fowler and Turvey give an excellent
description of control) and 2) why the hell are they publishing in
psychology journals instead of physics journals?

All
self-organization depends on negative feedback, and I don't consider it
control unless there is a variable reference level. For me, vortices
don't count as purposive.

I won't count this as another wrong, don't worry. The vortice doesn't
qualify as a control phenomenon because the loop gain is very low (less than
1). It is easy to build systems with fixed (non variable) reference levels
that unequivocally count as purposive (they CONTROL).

Care to empty your cup? The PCTea is still steeping.

Best

Rick

2

[Martin Taylor 931201 10:30]
(Rick Marken 931130.1900) and (Bill Powers 931130.1545)

(Rick)

So that makes three wrongs for you (wrong, wrong, wrong -- just what you
you expected me to say), still zero wrong for me. And, as everyone knows,
three wrongs don't make a wright.

Sorry, I'm the referee, not you. Three rights to me, zero to you. Does
that make me a (play)wright?

(Bill)

We're arguing about angels dancing on pinheads. Fooey on this.

Oh, but it is fun to watch the dance.

ยทยทยท

----------------
More seriously:

Remember the diagram (Martin Taylor 931129 11:45)

               > reference
               V
        ->-comparator-->- -<- energy source
       > > >
   perceptual output
    function function
       ^ | |
       > V V
======|=======etc=======|=|==
       ^ | |
       > power--<-- ----> energy sink
              to CEV

Take away the reference and the =====etc==== line, and complete the loop
with a minor renaming of the perceptual input function that in no way
affects its role in the loop.

        ->-comparator-->- -<- energy source
       > > >
    fed back output
     energy function
       ^ | |
       > V V
       ^ | |
       X--<--- power--<-- ----> energy sink
       > to stable
       > structure X
       >
    disturbance

You have a diagram of the energy flows in a self-organizing non-equilibrium
dynamic system. That's what a vortex looks like, for example. How is
this different from a control system without a reference variable?

(Rick)

Well, I don't mind if you give every vortex in a stream "purpose," but I
do think that this usage goes a bit beyond the normal bounds of the term.

Perhaps I should have said "high gain" -- that would eliminate the vortex.
But you missed the point anyway. You had said that purpose only arises from
a negative feedback systems with a VARIABLE REFERENCE. This is demonstrably
wrong. I can write a model of a control system with no explicit
reference signal -- and it still controls (exhibits purpose).

and

The vortice doesn't
qualify as a control phenomenon because the loop gain is very low (less than
1).

How do you know the gain? It surely is the ratio between energy that is
used to modulate the flow and the energy in the flow to the stabilized
structure. I don't think that eliminates the vortex, does it?

(Bill)

Vortices in a stream are not control systems. The energy upon
which they draw to maintain their stability is the same energy
carried by the forces that perturb them. That's not how a control
system works, as you pointed out yourself.

I'm not clear where you see "the same energy carried by the forces that
perturb them." Depending on how you think of "the total system" we are
all perturbed by the same energy on which we draw for control, or not.
After all, it all comes either from the sun or from the innards of
supernovae, and it all flows out to the cold of space. Or, at the other
extreme (where we usually prefer to look) there is an energy source
available to power the provision of energy to the single degree of freedom
that is the CEV, and another that powers the informationally independent
disturbance. You can look at the vortices the same way. The disturbing
energies come from the interaction of the stream flow with extrinsic
objects (tree branches in the river, wind gusts in the air) that are
well separated from the negative feedback loop and its energy sources,
the head of water or air pressure differential that powers the stream.

There's quite a difference between the stability of a vortex, based on
negative feedback within a high energy flow, and that of a marble in a
bowl, where energy is simply converted from the disturbance into the potential
of the marble, and then converted into heat as the marble fallas back and
comes to rest.

I still don't mind if you call what happens in the vortex "control" but
I don't like the assertion that it has "purpose." And I'd prefer to keep
the concept of "control" together with that of "purpose" rather than with
high-gain negative feedback loops, which are a major component of self-
organizing systems. Whatever you choose, I'll conform to your language.

Within any framework, any particular explanation may be in
error, and the error found by testing the explanation within
the framework. There is no ground for criticizing an
explanatory framework because the explanations within it do
not explain the things YOU want explained, if they explain the
things someone else wants explained.

This is a statement about mathematical frameworks, not about an
experimental science.

Oh? If I want to find out how a deep ocean current sustains itself,
rather than why Annie Corrie has a problem with her mother, I'm
doing mathematics rather than experimental science?

Our main
dispute with the dynamicists rests on the fact that we both
purport to be explaining the same observations, yet we have
arrived at mutually contradictory explanations.

If that is so, then my previous (and repeated) comment applies, about it
being legitimate to criticize wrong explanations. It's irrelevant
to whether it is legitimate to criticize the dynamics _framework_ for
explanation on the grounds that control is not explicitly explained.

One doesn't have to reject the dynamicists' framework to bring up
counterexamples, to show implications that are contrary to
observation, to point out that disturbances exist in normal
environments and that actions affect inputs at the same time that
inputs are affecting actions. These facts and relationships are
part of the data, not of the theory.

As I understand dynamic theory, these latter relationships are near
its foundation. I don't know what implications contrary to observation
you refer to, but as with any theory in any field, such implications either
are wrong developments from correct theory or are indicators of wrong
theory.

So what, if their results are interesting to them, and hold
whether or not particular variables are controlled.

...
if this is how people want to play the game, this is how they
will play it. But they will play it without me.

Sure. You are interested in phenomena that are best explained in
terms of control. They may not be. So they play without you, you
play without them. There should be no conflict, and no issue. It's
when the two systems make different predictions about what both think
ought to be the same thing that you can't play it without them, nor they
without you. One or other will find the confrontation with Boss Reality
discomifitng.

Inasmuch as "control" is a special case of dynamics, whatever
is true in general of dynamic systems must also be true of
control systems, though the reverse is not the case.

The idea that dynamic systems analysis says everything that
control theory says is a delusion.

I said exactly the reverse of what you call a "delusion."

If there were any statements that are true of all possible
dynamic systems, then of course they would apply to control
systems, too. But such general statements also have to apply to
systems that are not control systems, so they would be unable to
express what is different about a control system and, say, a
marble in a bowl or a billiard ball rolling along a flat table.

Yes, that's a more specific way of expressing my point.

(Rick)

The dynamicists
of whom you speak (the Kelso, Turvey, Kugler, et al type) are trying
to explain control (the phenomenon) using models that DON'T CONTROL.

Maybe so. I made no references to specific people, so they are not
"of whom I speak."

If their purpose were NOT to
explain control phenomena, then they would be physicists; they would
apply their models appropriately to non-control phenomena and I
would have (almost) nothing to be obnoxious about. But, as it turns out,
I am right (this time) and you (and the dynamicists) are wrong.

I'm not sure what you claim to be right about. And since I agree with
you that wrong explanations (explanations that misdescribe nature) are
wrong, then if I'm wrong, you are, too. (So I alter my referee's judgment
above to MMT 2.5, RSM 0.5).

I'm happy to call the reference level the purpose. But that just reveals your
statement "Perception is the way purpose is achieved" to be even more
profoundly wrong. It says that perception somehow guides itself toward
the reference level.

No. The control loop does that.

Your belief in information in perception is showing again.

I don't deny it. But that's a very curious use of the word "belief."

The closed negative
feedback control loop is the way purpose is achieved. Perception is
what is controlled.

Precisely. So I agree with you again. Too bad. MMT 2 RSJ 1 (or 3 2,
if we count a whole right each time we are both right.)

Try rereading the quoted sentence.

I only re-read the Bible, Shakespeare, Dr. Seuss and Bill Powers.

I had some such notion. That's why I seldom take your comments seriously
when they (as so often happens) claim to comment on things I write, but
in no way refer to what I wrote.

Care to empty your cup? The PCTea is still steeping.

I LOVE politically correct tea. Keep it warm for me. I'll be back.

(Bill)

We're arguing about angels dancing on pinheads.

Can you see them closely enough to know they are angels?

Martin