[From Bill Powers (2006.08.22.1130 MDT)]
Rick Marken (2006.08.22.0900) –
Your discussion of rights is
very interesting, and I agree with it. But it doesn’t really address my
question, which was about the relationship between perceptual variables
and our models of external reality. I am wondering whether you think any
perceptual variable can be considered objective in the sense that it
corresponds to something in our models of external reality.
I think that our models of external reality are intimately connected to
our perceptions. When we propose a model, we test it by seeing if it
predicts correctly the effects of our actions via external reality on
what we observe – that is, what we perceive. The basic paradigm of
model-based theorizing, which is basically experimental science, is
“If I cause this perceived act to occur, the model predicts
that I will perceive that consequence happening.” The
connection between the perceived act and the perceived consequence is not
visible; we are guessing at what exists in the realm beyond the basic
sense data. We have no direct way of checking: the prediction might be
right for completely wrong reasons.
Sometimes – quite often, actually – we become able to dissect some
black box in the environment so we can perceive its components, and we
discover that our model was mostly correct, in terms of the new
perceptions that are now revealed. Of course it also can happen that we
were entirely wrong, as in the case of phlogiston. The components are
more perceptions, of course, but it is encouraging that sometimes we are
able to predict what we will perceive that we can’t perceive now. We can
actualy penetrate the surface appearances to a new underlying surface.
It’s still a surface, and still just an appearance, but the fact that we
get to it by acting on the outside world does “lend an air of
verisimilitude to an otherwise bald and unconvincing narrative,” one
of Bob Clark’s favorite sayings.
By their nature, models contain guesses about entities that we can’t
observe. If we could observe all the entities, we wouldn’t need the
models. We’d just need to measure the relationships and write them
down.
But all relationships are relationships among perceptions, and what
causes the relationships to exist is not perceivable.
So our “models of external reality” are all guesses, and they
are all cast in the form of relationships among perceptions. We reify
some of those perceptions and give them names like force, acceleration,
distance, intensity, oxygen, and temperature. This gives us a feeling of
dealing directly with things in the world outside. Physicists, indeed,
speak as if those things are what is “real”, while what we
experience is imaginary. Of course the truth is the exact opposite. The
only reality we can know anything about directly is the world of
subjective experience.
I’m just interested in
hearing a discussion of the relationship between perception and reality
in PCT. I understand that many (most) perceptions, such as the taste of a
milk shake, are constructions based on sensed aspects of external
reality. There is no milk shake taste out there (according to our
models); just the molecules that elicit various taste sensations, which
are combined to produce the taste “milk
shake”.
The molecules are just another level of model, of course. There are no
molecules out there, either.
In your earlier discussion you
implied that some perceptions (like “rights”, assuming they are
perceptions) are less objective than others because these perceptions
don’t correspond to anything in our models of external reality. I was
just asking whether some perceptions are more objective than others. For
example, color could be considered an objective perception because
changes in color correspond to changes in what we model as changes in
wavelength of light. But we also know that a color perception that
corresponds to a single wavelength can also result from the appropriate
combination of 2 or 3 wavelengths. So it seems to me that color is no
more objective, in terms of correspondence between perception and model
of external reality, than the perception of a principle like “the
right to bear arms”. What do you think?
I agree that no perceptions are objective in the sense that they
constitute direct knowledge of the external reality. The nearest we can
get to objectivity is through methods (of science, mostly) that permit us
to define what we mean, and to specify procedure that anyone can carry
out to test various propositions. There is still plenty of room for
uncertainty; scientists often find that when they thought they had
agreement with some other scientist, they were really talking about
different things. It’s very easy to get agreement, but very hard to
determine exactly what has been agreed to.
I had been arguing earlier for
the idea that perception can be objective in the sense that people can
agree (often after much discussion, pointing and whatever) that they are
having the same perception (such as “the meter reading is 25
amps”).
Meter reading? 25? Amps?
And I think in most of
these cases they are having the same perception.
You do? You may hope that they are, and have faith that they are, and act
as if they are, but I defy you to demonstrate that they are.In fact I see
no reason to assume that perceptions are similar at all in any two
people.
I don’t know how to put this – Richard Kennaway can probably do it
better than I can. It’s a degrees of freedom problem, only the opposite
from the case where there are too few degrees of freedom in the
environment. When the environment has more degrees of freedom than our
perceptions have, as I think is the case, when you and I control
“the same thing,” our perceptions can be completely different
from each other. You can see this in the ThreeSystemsC.exe program, which
shows that a three-dimensional control system can be blind to rotations
in the environment, while still keeping its perceptions matching its
reference levels.
So I think this kind of
“inter-observer agreement” objectivity exists but that the
“correspondence of perception to external reality” type
objectivity probably doesn’t… What do you think?
What I’m hoping for (I want reality to be knowable as much as you do) is
that we will find a way to show that when multiple control systems share
an environment, resolving the conflicts among them will end up
eliminating the differences between the perceptions in the different
systems. Maybe this will still leave ambiguities of a fundamental kind,
but with billions, or even just thousands, of observers and actors
interacting, we might actually exhaust the untapped degrees of freedom in
real reality.
Until we can show that, however. I have to remain a skeptic, no matter
what I want to be the truth.
Best,
Bill P.