>The appearance of this "two way causation" can be explained in the
>following way. Imagine a complex dynamic system. The trajectories of the
>system through its state space are constrained by the "laws" of the
>dynamics. These dynamics in general determine a set of "attractors":
>regions in the state space the system can enter but not leave. However, the
>initial state of the system, and thus the attractor the system will
>eventually reach is not determined. The smallest fluctuations can push the
>system either in the one attractor regime or the other. However, once an
>attractor is reached, the system loses its freedom to go outside the
>attractor, and its state is strongly constrained.
>
>Now equate the dynamics with the rules governing the molecules, and the
>attractor with the eventual crystal shape. The dynamics to some degree
>determines the possible attractors (e.g. you cannot have a crystal with a
>7-fold symmetry), but which attractor will be eventually reached is totally
>unpredictable from the point of view of the molecules. It rather depends on
>uncontrollable outside influences. But once the attractor is reached, it
>strictly governs the further movement of the molecules.
>
>
You make a good point about the limitations of reductionism with respect to
emergent properties.
What you describe about dynamic systems sounds very much like what Chris
Langton (and others) of the Santa Fe Institute found concerning the
optimization "attractors" that appear during the evolution of genetic
algorithms. I think that the surprising phenomena of self-reinforcing
emergent order is a natural process of evolution, given entropic
environmental forces that also serve as selectors for certain structural
stabilities. At one time I thought I was the first to assert that evolution
was an entropic process until I learned that this was not a new idea, having
been advanced by several (cf. Wiley & Brooks). The thermodynamics of
evolving order are described by Murray Gell-Mann (Quark & Jaguar) and I.
Prigigine (Order out of Chaos) - most compatibly, in my opinion.
Mike