The 20 Ways/Assumptions of the Magical World View – Law #5
If it works, it is true.
A world view is only valid if it enables its perceivers to accomplish their goals. The more successful a world view is in fulfilling the goal structure that its viewers possess, the more valid it could be said to be. By this definition, few people could be said to be completely insane. However, few people could be said be completely sane, either.