Looking back to data, we can see if the consequences are plausible; looking forward to theory, we can see if general principles are suggested.

Unwrapping occurs when the "solution" is explicitly built into the program from the start.

nonlinear interactions almost always make the behavior of the aggregate more complicated than would be predicted by summing or averaging.

With theory, we can separate fundamental characteristics from fascinating idiosyncrasies and incidental features. Theory supplies landmarks and guideposts, and we begin to know what to observe and where to act.

Looking back to data, we can see if the consequences are plausible; looking forward to theory, we can see if general principles are suggested.

Model building is the art of selecting those aspects of a process that are relevant to the question being asked. As with any art, this selection is guided by taste, elegance, and metaphor; it is a matter of induction, rather than deduction. High science depends on this art.

This use of building blocks to generate internal models is a pervasive feature of complex adaptive systems.