[Hans Blom, 950621a]
(Bill Powers (950614.0630 MDT))
... The environment does not have the power to act on an
organism in such a way as to make it do any specific behavior.
No. Yes. Depends. At least upon what you consider "environment".
How about:
Person A does not have the power to act on person B in such a
way as to make person B do any specific behavior.
Long discussions have been fought over this in the past, I know.
Words, words, worse. Less than convincing. Cooperation between
people does exist, is indeed required for tasks that cannot be
done by one person alone.
My position is that the better you know the laws that govern the
behavior of a particular someone -- indeed, PCT points out that
it may be sufficient to know that person' goals -- the easier it
is to influence that person's behavior. Now influence is only
partial control, of course, but who would want full control? Full
control would mean that you have to do everything all by yourself
again...
To say that we "filter out" perceptions implies, to me, the
wrong model of perception and the wrong epistemology. The brain
has to labor mightily to bring order into the field of
intensity-signals where all potential perceptions exist.
Maybe I ought to say "labor mightily" rather than "filter out",
but I doubt whether that would be clearer for most ;-).
Each perceptual function that creates a stable perception in a
changing world is a triumph of invention, an accomplishment by
the organism. The organism must contain some very powerful
machinery in order to bring about this result. If it were not
for this machinery, we would have no perceptions of the world
above the level of intensities and perhaps sensations.
I would express this differently, more generically, I think, em-
ploying words like "building up internal knowledge" rather than
paradigm-dependent words like "tuning a perceptual function", but
basically I agree with you completely.
"Filtering out" refers to pruning unwanted perceptual connections
from a perceptual input function rather than building up its con-
nections. Basically negative versus positive, certainly NOT a
very different paradigm.
The PCT position, however, is constructivist in the sense of von
Glasersfeld's Radical Constructivism. In order for a perception
of any given kind to exist, the brain must explicitly construct
a perceptual function which creates a signal that is a function
of lower-level signals.
Explicitly construct or explicitly prune, what's the difference?
In a model based approach, connections initially have any value
(and a large variance), but after learning, that value has settled
down (and has a small variance). That's more like pruning away
uncertainty than it is building up certainty. But let's not fight
over words where we basically agree.
Nothing Erling or Hans said directly asserts the naive-realist
view, but the idea of "filtering out" really belongs to that
view.
I don't think so. A different interpretation is possible.
A more general argument [for a hierarchical organization of
control systems] comes from the fact that human control systems
have to be general-purpose systems. There is no single "plant"
with which the system interacts; the "plant" consists of all
possible (local) environments in which the organism might find
itself.
Not convincing. The single "plant" of an organism is the earth,
and there are a great many commonalities between different local
environments on earth. There are differences as well, of course,
but humans fare equally well in the Arctics, in the Kalahari and
in New York (well, maybe not New York :-). I guess that this is
another case of where you say that X is more important than Y,
whereas I think the opposite. In other words, your argument is
not convincing _for me_.
The great disadvantage of the single-level approach is that the
whole system must be organized specifically for one environment,
one plant.
Try this: There is only one plant, but the plant's characteristics
can change, requiring renewed learning in a different environment.
This interpretation is at least as plausible to me. Since the plant's
characteristics change OVER TIME and we have to adapt to that, why
not use the same adaptation mechanism when the plant changes OVER
POSITION?
Greetings,
Hans