[Hans Blom 930616]
(Rick Marken (930615.0900))
I think you are pointing out
that both cells and people are control systems -- which I accept
as true.
This is not exactly what I'm trying to say. What I mean is that both cells
and people can be MODELLED as control systems, and in quite comparable
ways. What cells and people ARE will, in my humble opinion, remain beyond
my understanding (i.e. modelling powers) forever.
The behavior of collections of cells (such as the cells that
make up an organ, like the liver) is regulated by systems external
to the cells.
That is not what I perceive. I see that cells live in and depend upon an
environment (mainly of other cells), and that they, in turn, shape that
environment for the other cells in the collection. My perception is more
that of a collection of interacting autonomous agents, very much like in
the CROWDS or GATHERINGS programs. If the cell does not agree well with its
environment, it may become sick, and the products of its sickness in turn
may deteriorate the other cells' environment. What all individuals share is
a common environment that works two ways: it influences and is influenced
by each individual. Through this common environment, cells must necessarily
influence each other. I therefore do not agree with your statement
I agree that the behavior of collections
of cells is regulated by other systems -- the collectives are part of
a higher level control system.
There is no higher level control system, there is just a common
environment. I agree with you when you see no evidence of higher level
control systems. So why postulate them?
I'm perfectly willing to believe that there
are such higher level social control systems. I just don't see any
evidence of them. I see no evidence of side effects of collective
action being under control. The results of collective action that I
have seen controlled seem to be controlled by the individuals
themselves.
Collectives build common environments and if they cooperate (have common
goals) they can, indeed, create a skyscraper or a symphony, something that
no single individual would be able to do. Thank you: a skyscraper or a
symphony is a nice example of an 'emergent' result of cooperation of
individuals!
(Bill Powers (930615.0900 MDT))
The cells in a body (for example,
liver cells) receive reference signals from superordinate systems
like the pituitary that specify for those cells the level of
their controlled variables that they are to maintain (blood
glucose concentration).
Why do you say that they receive REFERENCE levels? In my opinion, cells
receive perceptions. Their reference levels are 'built in'. The analogy
with people is, in this respect, complete. I'm very curious about your
reasoning on this point.
Liver cells are responsible for
maintaining the specified level of input, but they have no say
about what level will be specified.
Who tells the liver cells that they are responsible for other cells or for
some grand collective? I think that you are anthropomorphizing. Let me
assure you, liver cells LIKE to do what they do! They are not slaves that
are responsible but have no say. Neither would they want to be, say, brain
cells 
Greetings,
Hans Blom