"Any fool can criticize, complain, and condemn--and most fools do. But it takes character and self-control to be understanding and forgiving."

"The trouble with most of us is that we would rather be ruined by praise than saved by criticism." 

"We need very strong ears to hear ourselves judged frankly, and because there are few who can endure frank criticism without being stung by it, those who venture to criticize us perform a remarkable act of friendship, for to undertake to wound or offend a man for his own good is to have a heal...

"The critic has to educate the public; the artist has to educate the critic."

"The final proof of greatness lies in being able to endure criticism without resentment."

"Criticism may not be agreeable, but it is necessary. It fulfills the same function as pain in the human body. It calls attention to an unhealthy state of things."

"Criticism, like rain, should be gentle enough to nourish a man's growth without destroying his roots."

"If you have no will to change it, you have no right to criticize it."