A man had need have sound ears to hear himself frankly criticised; and as there are few who can endure to hear it without being nettled, those who hazard the undertaking it to us manifest a singular effect of friendship; for βtis to love sincerely indeed, to venture to wound and offend us, for our own good. I think it harsh to judge a man whose ill qualities are more than his good ones: Plato requires three things in him who will examine the soul of another: knowledge, benevolence, boldness.
~ Montaigne, The Complete Essays (1587-88)