[Martin Taylor 2017.11.30.09.57]
I'm continuing the "powers 1973" thread here because I think the avoidance topic is different. After imbibing what various people have said about avoidance, my own ideas seem to have changed. Here's what I now think (tomorrow I may disagree, as I now disagree with what I thought a few days ago, and with what I thought when I started writing this message yesterday).
Right now, I think "avoidance" must be discriminated from "removing oneself from a situation". Also it must be discriminated from controlling to produce a perceptual value of zero for the perception to be avoided. Why? Because the "to be avoided" perception is not now being perceived, so no action is required to change it. The "avoider" may be (in fact presumably is) controlling for the value of the perception to be zero, but it is already zero and no change of output is required. If the value of the "to-be-avoided" perception stops being zero, the actor has failed to avoid it. Controlling to avoid (perhaps a better phrase than "control of avoidance") is not acting to get away from a bad situation, (as claimed in [From Rick Marken (2017.11.30.1930)] but acting now to prevent the bad situation from occurring later.
Avoidance is planning, planning not to get into a future situation that (in imagination) would create error in some controlled perception. Erling's examples [From Erling Jorgensen (2017.11.30 0735 EST)] of ship control and air traffic control, both to avoid collisions, are of that kind. What is involved in this planning? So far as I can see, it is controlling in the "now" world so that the future world has a lower probability of producing the to-be-avoided perception. It's not "getting away" from anything, as I (and Jeff and Rick) had conceived it.
Jeff's berry picker may well be controlling for low proximity to a bear, but is not currently perceiving the bear. The age of the bear tracks may be perceived and used as part of a perception of how far the bear probably is, but the to-be-avoided perception is of the charging bear, a perception presently existing only in the picker's imagination. Erling's traffic controller controls a perception of the aircraft maintaining positions within their traffic lanes at prescribed distances so that there is low probability of their colliding. "To-be-avoided" is the future perception of a collision, not the correction now of a perception that there has been a collision so that there has not.
Similar, I think, are all the examples in my list except the first, which presumes "I" am already in the crowd and am currently controlling for low proximity to all the other people in the crowd. In all the others, what "I" do to avoid the bad situation is either control some perceptions of the current state of the external world or resolve an internal approach-avoidance conflict in imagination. Both of those are actions in the "now", but they aren't corrections of a "now" error in perceptions based on the current environment. The berry-picker may run away from very fresh bear tracks, "I" may choose to take Dora to a restaurant I know Rachel does not frequent. These are actions in the "now". They are "live" control to produce environments in which "I" perceive the to-be-avoided perception to be unlikely to occur.
As I see it today, controlling to avoid is part of the question of planning, control in imagination, and how control in imagination influences "live" control. "Avoiding" is not acting to remove oneself from a situation one does not want to perceive.
Martin