[From Bill Powers (950227.2000 MST)]
... we do quite
often experience changes in our perceptions that we didn't intend to
happen. That is evidence of something existing independently of us.
I don't think it is evidence at all. A solipsist would be quite
happy to assert that these "unexpected" happenings are just the way
our inventiveness allows us to believe that there is something out
there.
Yes, I've heard that one before. Does the solipsist really think that is
a convincing proposal? It can't be supported by evidence. If we took
that one seriously, we would also have to wilt before an assertion that
there is a secret society living on the other side of the moon that is
making us think we are human beings living on Earth, when we're really
dogs living on Mars.
If we go by rules of demonstration and evidence, the solipsistic
position doesn't have a chance (and I don't understand why anyone ever
considered it a serious argument). What a solipsist is happy to assert
is up to the solipsist, but since anyone can assert anything, we need
not take all assertions as propositions to be coped with. The solipsist
has made a claim; let him support it.
My criteria for establishing evidence for an independent reality are
quite simple, and people use them all the time. First, when we decide to
control some perception, we find that we must learn to use certain
actions and not others; some work and some don't. This tells us that
there are rules we didn't make up, although we can discover later that
our original conception of the rule was too elaborate or included
unncessary actions. The point is that we do not have a free choice of
action once we have decided what consequences we want to experience. So
there is a constraint on our ability to control and that constraint is
external to us.
Second, when we are observing the world we see things happening in it
that we can't attribute to our own actions: sunrise and sunset, for
example, or wind and rain, or other people's opinions. We couldn't cause
such things to happen if we wanted to. If you see a blanket on the sofa
and a lump in the blanket begins to move, it is perfectly reasonable to
assume that there is some independently mobile thing or organism under
the blanket. It's probably my cat. We can be wrong about such
assumptions, but generally we're right. We can control some experiences,
but not others. The difference is whether we can affect them by using
our muscles. The ones we can't effect, but that happen anyway, are
independent of us.
I can present quite ordinary evidence in support of my judgment about
the existence of an independent reality. To offer evidence for the
solipsistic point of view is by definition impossible, so we either must
dismiss it out of hand, or give up relying on evidence. I prefer the
former.
···
-------------------------------
Personally, I find that I cannot imagine any kind of evidence that
would make "out there" as opposed to "in here" a more probable
source of perceptions.
The problem is that the solipsist position, like the instantaneous
creationist position, is an intellectual dead end.
I think the problem is that the solipsistic position can be asserted,
but it can't be defended. Any defense relies on a statement of fact
which is assumed to be true independently of the observer: the statement
that we are generating the experiences ourselves. If that is true, then
there is one fact of nature that is true independently of us, the fact
that we are deluding ourselves. Thus solipsism is disproven by self-
contradiction.
I think it is important to stay with your choice (1), modified to
admit that we can infer existence without knowing form, because doing
so forces us to be clear about the distinction between perception and
imagination, between observation and inference.
That contradicts my (1), but I see no difference between it and my
(2).
I will try to explain the difference. Your (1) deals only with the
EXISTENCE of an external reality, claiming that we cannot know whether
it EXISTS. My substitution says that we CAN infer its EXISTENCE by legal
moves, but that we can't assert that we know its FORM. That is, I can
show that there is something independent of me making the lump in the
blanket move, but I can't show that it is my cat (without lifting the
blanket, which in the important cases can't be done).
Your (2), on the other hand, assumes, for convenience, that perception
represents both existence and form. This leaves out the case where we
perceive one form, but it is a transformation of some quite different --
but still existent -- form. The effect of the difference between (1) and
(2) is not on perception: I agree, it's all perception. It's on what we
infer about the nature of the real world.
As to the difference between inference and perception, this is a matter
of classifying experiences, not a statement about reality. When we are
perceiving we are attending to inputs from a place independent of us.
When we infer, we are thinking about those perceptions. It is not hard
to tell the difference. Thinking is one kind of activity and perception
is another. If I see an apple with a brown spot on its surface, I am
perceiving. If I see a rotten apple, I am inferring something I can't
perceive. That's all I mean.
-----------------------------------
I'm afraid I didn't understand Bill L's comment, and neither do I
understand Bill P's agreement with it.
Bill Leach is on a roll; I'll leave it to him to explain. That also
saves me the trouble of recreating the reason for agreeing with him.
-----------------------------------------------------------------------
Richard Thurman (950227.0915)--
Memory seems (to me) to be external to PCT.
I agree. Memory came up in answer to a basic question I asked myself
long ago: what is required in order to "do the same thing" twice? Once
we recognize that the environment is changeable we can't simply say
"reproduce the same action." But even if we could, we would have to
explain what is meant by "the same." The only answer I could see was
"the same as the last time." And how can we, now, know what happened
"the last time?" Only by remembering what happened. And that is how
memory got tied into reference signals. But memory itself, from which
reference signals can be drawn so as to recreate a former perception, is
extraneous to the model; it has to be explained in some way outside the
range of PCT.
... an RNA model of memory is no longer considered a contender.
Can't win them all. How about glial cells, which outnumber neurons in
the brain 10:1?
I have for some time tried to get a handle on what PCT can do to
help the learning/teaching situation.
I think that one productive line of enquiry might come from
concentrating on _what is learned_. From the PCT point of view, what is
learned must always be perceptions, not actions, for actions must be
free to change as disturbances change. So "getting the right answer" has
to be seen as learning what it is you will be perceiving when the answer
is right. How will you know when you have successfully learned
something? If that is spelled out clearly, finding out how to achieve
that perception even under changed conditions may be much easier.
Also, I have felt for a long time -- since BCP -- that if the learning
in question is simply a matter of memorization, then well-known
techniques for memorization should be used. They work beautifully, and
they work quickly. Why spend an entire year learning the multiplication
tables when they can be memorized by the method of loci applied ten
minutes per day for one week? A big steel "9" is stuck like an axe into
the door of the little bathroom, and inside, a locomotive with 9 really
tiny wheels under the sink is making 81 little puffs of smoke. On the
other hand, an eight-sided mirror on the wall in the same room shows you
the reflection of a 72-year-old dog. There are lots of ways to do this.
My theory is that the details are providing addresses for the accession
of specific memories. But who cares? It's easy, fun, and fast.
What do you see in the eight-sided mirror?
Which room goes with "9", and why?
What are the 81 puffs of smoke coming from?
Instant memorization.
---------------------------------------------------------------------
Best to all,
Bill P.