"Every evil act tends to harden man's heart, that is, to deaden it. Every good act tends to soften it, to make it more alive. The more man's heart hardens, the less freedom does he has to change; the more is he determined already by a previous action. But there comes a point of no return, when man's heart has become so hardened and so deadened that he has lost the possibility of freedom, when he is forced to go on and on until the unavoidable end which is, in the last analysis, his own physical or spiritual destruction."
-- Erich Fromm