Feuds seem to feed on the heart's acidity and bitterness, so they do not occur when there is absolute frankness. Those who do constant maintenance work on the heart, removing its acidity, are able to neutralize many opportunities for conflict, because they are utilizing their emotional and spiritual immune systems. This is a spiritual, somatic reality. The neglect of spiritual health leads to the development of emotional and affective difficulties. Criticizing others effectively is the best means for the removal of acidity from the heart.
— Nilton Bonder, The Kabbalah of Envy