“When the ego has taken its defensive measures against an affect for the purpose of avoiding unpleasure, something more besides analysis is required to undo them, if the result is to be permanent. This child must learn to tolerate larger and larger quantities of unpleasure without immediately having recourse to his defense mechanisms. It must, however, be admitted that theoretically it is the business of education rather than of analysis to teach him this lesson.”
—Anna Freud (1966, pp. 64-65)
Freud, A. (1966). The ego and the mechanisms of defense (revised ed.). New York: International Universities Press.