[From Ellery Lanier (960930.1:30MST)]
I want to thank Bruce Abbott for the info on Dewey. Gave me pause for
reflection.
I actually took a class with him. It could have been 1934. Makes me feel
real ancient.
I don't think I had the slightest idea of what he was talking about, but maybe
whatever took hold accounts for my pleasure in finding the writings of
Bill Powers.
Ellery
[From Bruce Abbott (960930.1545 EST)]
Rick Marken (960930.1000) --
Dewey's main "revelation" in the quoted passage seems to be that sensory
effects cause actions _while_ those actions cause sensory effects; he
understood, in other words, that behavor occurs in a causal loop. The only
problem, of course, is that he had no idea this meant that behavior is the
control of these sensory effects.
I think you are being much too critical of Dewey. In the first place, his
recognition --in 1898-- that sensation and action exist in a closed loop put
him about 50 years ahead of his time, and control theory itself was still
around 35 years into the future. It is no small intellectual achievement
that Dewey should have arrived at this insight at a time when virtually
everyone else (perhaps excepting James) had bought into the S-R reflex
concept lock, stock, and barrel. I find Dewey's insights every bit as
amazing as James's.
Although Dewey describes behavior in closed-loop terms, he clearly didn't
know how to deal with this closed loop because he falls right back into a
cause- effect description of the reflex arc toward the end of his discussion:If the sight did not inhibit as well as excite the reaching, the latter
would be purely indeterminate,
So, when Rick Marken states that the error signal determines the action and
that the action in turn affects the controlled variable, we should all
assume that he "[doesn't] know how to deal with this closed loop because he
falls right back into a cause-effect description"? Of course not. But when
Dewey talks like that you are ready to leap enthusiastically to this
conclusion. Why? Because you don't want to believe that Dewey might have
had it right.
The discussion up to this point may be summarized by saying that the reflex
arc idea, as commonly employed, is defective in that it assumes sensory
stimulus and motor response as distinct psychical existences, while in
reality they are always inside a coordination and have their significance
purely from the part played in maintaining or reconstituting the coordin-
ation; and (secondly) in assuming that the quale of experience which
precedes the 'motor' phase and that which succeeds it are two different
states, instead of the last being always the first reconstituted, the
motor phase coming in only for the sake of such mediation.
In other words, each affects the other, with the "motor phase" coming in
only to alter the "quale of experience" (perception).
Later Dewey has this to say, when describing running from a sound that one
has taken to indicate the presence of wild beast or robber:
The motor reaction involved in the running is, once more, into, not merely
to, the sound. It occurs to change the sound, to get rid of it.
And again:
The fact is that stimulus and response are not distinctions of existence,
but teleological distinctions, that is, distinctions of function, or part
played, with reference to reaching or maintaining an end.
I think you are right about one thing, however: In reading Dewey's paper it
is only through certain indirect statements that any notion of "reference"
comes through, as in the above passages. He repeatedly emphasizes the point
that experience and motor response form a closed circuit, each affecting the
other to produce the _act_ of seeing, or reaching, or doing whatever, but
never explicitly mentions anything about what, within the loop, represents
the end to be accomplished. However, as you were so willing to forgive
James for not having the benifit of control theory to guide his thinking, I
am puzzled as to why you do not wish to give Dewey the same consideration.
Could it be merely that James is on the current "approved" list of those who
early on offered ideas later to become central parts of control theory, and
Dewey is not? Alternatively, does Dewey's potential inclusion threaten your
controlled perception that no "conventional" psychologist outside of James
ever had a "clue" that perception and action exist in a closed loop of
causation?
Regards,
Bruce
[From Rick Marken (960930.2210)]
Bruce Abbott (960930.1545 EST)
So, when Rick Marken states that the error signal determines the action and
that the action in turn affects the controlled variable, we should all
assume that he "[doesn't] know how to deal with this closed loop because he
falls right back into a cause-effect description"? Of course not. But when
Dewey talks like that you are ready to leap enthusiastically to this
conclusion. Why? Because you don't want to believe that Dewey might have
had it right.
I know Dewey didn't have it right. But I forgot to mention that you don't
have it right either. The error signal in a control loop is a cause of the
action that influences the controlled variable. But you and Dewey both make
the mistake of assuming that a perception of "error" (distance from reaching
hand to object) causes the reaching action. This is the cause-effect
descsription of behavior that I say is wrong. It is wrong because perception
(such as the perception of the distance from hand to object) does not cause
the action in a control loop; the _difference_ between perception and a
reference for that percpetion (error) causes action.
Dewey was certainly not the last person to understand that behavior occurs
in a closed loop _and_ make the mistake of assuming that perception (of
"error") causes behavior. This mistake was (and still is) the basis of manual
control theory. If Dewey and the manual control theorists had said that
_internal_ error (the discrepency between perception and reference) is
the cause of action then I would have no complaint; then they would have
surely figured out that the perceptual variable in a control loop is not a
cause of action but, rather, a controlled result of action. But that's
not what Dewey, the manual control theorists (or you;-)) said. Ergo, my
complaint.
Best
Rick