I am amazed at the heart of man: It possesses the substance of wisdom as well as the opposites contrary to it ... for if hope arises in it, it is brought low by covetousness: and if covetousness is aroused in it, greed destroys it. If despair possesses it, self piety kills it: and if it is seized by anger, this is intensified by rage. If it is blessed with contentment, then it forgets to be careful; and if it is filled with fear, then it becomes preoccupied with being cautious. If it feels secure , then it is overcome by vain hopes; and if it is given wealth, then its independence makes it extravagant. If want strikes it, then it is smitten by anxiety. If it is weakened by hunger, then it gives way to exhaustion; and if it goes too far in satisfying its appetites, then its inner becomes clogged up. So all its shortcomings are harmful to it, and all its excesses corrupt it.
~ Ali Ibn Abi Talib
