The Maximum Power Principle (MPP) is a proposed principle of open system thermodynamics.  While I only ever use the concept as it pertains to lifeforms, the principle is theoretically broader than that.  In biology, the essential idea of the MPP is that evolution invariably works so that any and every species will extract the maximum amount of available resources from their environment that they can in the shortest time.  (For more details, see the Wikipedia entry.)

source: Alfred J. Lotka (1922)

This principle is related to (but not the same as) my characterization of number-based value systems being subject (by definition) to the principle that More is Always Better.  For a discussion of their relationship, see here.