Organizing Principle

Info source: http://en.wikipedia.org/wiki/Organizing_principle

An organizing principle is a core assumption from which everything else by proximity can derive a classification or a value. It is like a central reference point that allows all other objects to be located, often used in a conceptual framework. Having an organizing principle might help one simplify and get a handle on a particularly complicated domain. On the other hand, it might create a deceptive prism that colors one's judgment.