Evolution, Positive Feedback

[From Rick Marken (960308.1100)]

Lars Christian Smith (20:30 CET) --

Dennett states that,

"Darwin's dangerous idea is that Design can emerge from mere Order via an
algorithmic process that makes no use of pre-existing Mind."

What is "Design"? What is "Order"? What is "Mind"? (At least, what are these
things according to Dennett).

The way I read it, it sounds like Dennett thinks that Darwin's dangerous
idea is the very idea that control theory shows is wrong: the idea that
intentional behavior can be explained by causal processes.

I read Dennett's quote this way for the following reasons. First, I think
that the word "Design" typically refers to an _intended_ result; when we say
that something (like a house or an eye) was designed we mean that it was
intended; the result (house, eye) was produced "on purpose".

Second, when Dennett says that "Design can emerge from mere Order" it sounds
to me like he is saying that intended results (or what appear to be intended
results) can emerge from the operation of orderly processes. I get the
impression that what Dennett means by Order is what we refer to as "causal".
So it seem to me that Dennett is saying that Darwin's dangerous idea is that
intended results (results produced by design) can be produced by ordinary
causal processes. [It is true that what _appear_ to be intended results can
be produced by such processes; but as we all know, _actually_ intended
results can only be produced by closed loop control processes).

Third, Dennett goes on to say that Design (indended results from my point of
view) is not the result of a pre- existing "Mind". I take "Mind" to refer to
a "purposeful system". So I understand Dennett to be claiming that Darwin
shows that intended results can be produced with no purposeful system (Mind)
involved.

If Dennett thinks Darwin's dangerous idea is that causal processes can
produce intended results then he's right; this is a dangerous (well,
unfortunate) idea and it already has had acorrosive effect on all of the life
sciences.

But I don't think this was really Darwin's idea. I think Darwin's (possibly
"dangerous") idea was simply that species evolve by natural processes, with
no supernatural design (purpose) involved. I'm quite sure that this general
idea is correct. I'm just not sure that Darwin came up with the correct (or,
more likely, complete) model of this process. I believe that natural
"selection" ("filtering" would be a better term) is involved in evolution;
but I like the idea that evolution (visible changes in species over time) is
a visible side effect of a molecular control process; the purpose (literally)
of speciation is in the genes.

G. Scott Graham (960308) --

I am having trouble seeing how this [donkey example] exemplifies an increase
in deviation from the intial status quo.

I presume you are responding to Hans Blom (960307). It's easier for me to
follow the conversation when people reference the posts or parts of posts to
which they are responding.

You are correct in noting that the donkey example involves only negative
feedback. I think positive feedback is relatively rare in behavior. What is
far more common is _conflict_ between negative feedback systems. Conflict can
look a lot like positive feedback because outputs continue to increase in
opposition to the outputs of the opposing system. The behavior of these
outputs can look like runaway positive feedback (as when the forces exerted
by opposing arm wrestlers skyrocket to maximum) but it's just good old
negative feedback systems working hard to reduce error.

Best

Rick