The Law of Balance is simply a statement for conserving personal energy and achieving the greatest proficiency. One’s energy or power level must be kept on an even keel, too much or too little will kill oneself.
This energy level is best maintained by avoiding extremes in thinking and action. One must be open minded, able to consider all alternatives, but strong enough to determine one’s personal course in life. This requires the right amount of flexibility to be able to examine new ideas or concepts in order to keep the ones which would improve one’s life and reject those that would not. In short, one never goes off on deep ends.
(See The Laws of Magic.) A.G.H.