The fast layers innovate; the slow layers stablise. The whole combines development with continuity.

"When a design problem resists solution, reframe the problem in such a way that it invites solution...An example of spontaneous reframing occurred in 01969, when the Apollo program began returning color photographs of the Earth from space. Everyone saw the photographs and saw that we occupied a planet that was beautiful, all one, very finite, and possible fragile."

"Things that are good have a certain kind of structure.
You can't get that structure except dynamically. Period.
In nature you've got continuous very-small-feedback-loop
adaptation going on, which is why things get to be harmonious.
That's why they have the qualities we value.
If it wasn't for the time dimension, it wouldn't happen.
Yet here we are playing the major role creating the world,
and we haven't figured this out. That is a very serious matter."

Christopher Alexander
[S. Brand, "How buildings learn", p.21, 1994]