" If a system is to deal successfully with the diversity of challenges its environment produces, then it needs to have a repertoire of responses (at least) as nuanced as the problems thrown up by the environment. So a viable system is one that can handle the variability of its environment. Or, as Ashby put it, only variety can absorb variety. "

― John Brockman , This Idea Is Brilliant: Lost, Overlooked, and Underappreciated Scientific Concepts Everyone Should Know