Subject: Do We Want to Talk about the

Posted by John Gunkler on 2/9/2006
In Reply To:Do We Want to Talk about the "Purpose" behind the Change? Posted by Ford, Andy on 2/9/2006

Message:

I agree wholeheartedly with Andy Ford that we do not need to resort to the language of "purpose" (itself a VERY slippery term!!) and that Dr. Forrester's formulation works fine as it is.

I would just remind everyone of the obvious (which may have been behind Jeff Levin's suggestion about "purpose"), namely, that negative feedback loops can all be considered to be "goal-seeking." And you can figure out what the goal is by seeing what state the loop is in when it is in equilibrium.

As John Sterman writes in Business Dynamics (p. 111-112), "Negative feedback loops act to bring the state of the system in line with a goal or desired state. ... Sometimes the desired state of the system ... [is] explicit ... . Sometimes the goal is implicit ...."

We are less comfortable calling positive feedback loops "goal seeking" but, in a sense, they are. It's just that their goal is infinite.

Once we get beyond simple (first-order, one-stock) feedback loops, the behavior can be much more complex. For example, in oscillatory behavior modes there is certainly change occurring, but we may have difficulty ascribing a "goal" to the system. The way to save "goal-seeking" language here is to accept the idea that the "goal" is to achieve oscillations of a certain frequency and amplitude.

That said, it's not beyond my ability to accept the idea that for any system that eventually will reach an equilibrium (if undisturbed for a long enough, perhaps infinite, time), we could call that equilibrium state the "goal" of the system. This would seem to encompass just about every system except chaotic ones, and even some of them (the ones with "strange attractors" for instance) have a kind of equilibrium state.

So, chaotic systems aside for the moment, what dynamic systems are there in the natural world that are not goal seeking, in this expanded sense? And, if they are goal seeking, isn't it a good bet that there is at least one feedback loop at work?

I haven't worked it out yet, but I also believe that in order to create the conditions for chaos, a system must also include feedback. There is a fundamental recursiveness to chaotic systems, I think, that could be formulated as feedback.

John Gunkler

Follow Ups:

Do We Want to Talk about the - Richard Turnock 2/25/2006 
Do We Want to Talk about the - Ashis Sen 2/25/2006 
Do We Want to Talk about the - Jay W. Forrester 2/17/2006 
Do We Want to Talk about the - Ashis Sen 2/25/2006
Do We Want to Talk about the - Michael Round 2/19/2006
Do We Want to Talk about the - Jay W. Forrester 2/25/2006
Do We Want to Talk about the - Louis Macovsky 2/27/2006
Do We Want to Talk about the - Louis Macovsky 2/25/2006
Do We Want to Talk about the - Louis Macovsky 2/27/2006