"The final frontier may be human relationships, one person to another." - Buzz Aldrin, Astronaut

This mutual understanding is a universal bond, which could not be removed without the community falling to pieces; it is force of cohesion permeating the structure of society, so that if this force were to cease to act, the whole mass would crumble into dust.  We therefore place this Need of a Mutual Understanding among the principal springs of human action.  from “The Elements of Morality, Including Polity” (1864) by William Whewell