While criticism or fear of punishment may restrain us from doing wrong, it does not make us wish to do right. Disregarding this simple fact is the great error into which parents and educators fall when they rely on these negative means of correction. The only effective discipline is self-discipline, motivated by the inner desire to act meritoriously in order to do well in one's own eyes, according to one's own values, so that one may feel good about oneself may "have a good conscience.
Bruno Bettelheim