The “balance wheel of all behavior”

The third element of the utterance under discussion is, “opposes his passions.” How wonderful are the implications of this deceptively easy, all-inclusive phrase. This is the very foundation of every laudable human quality; indeed, these few words embody the light of the world, the impregnable basis of all the spiritual attributes of human beings. This is the balance wheel of all behavior, the means of keeping all man’s good qualities in equilibrium. 
('Abdu'l-Bahá, The Secret of Divine Civilization)