Mencius - Book 4, Part 2, Chapter 28B

He examines himself, and is specially benevolent. He turns round upon himself, and is specially observant of propriety. The perversity and unreasonableness of the other, however, are still the same. The superior man will again turn round on himself "I must have been failing to do my utmost."

'He turns round upon himself, and proceeds to do his utmost, but still the perversity and unreasonableness of the other are repeated. On this the superior man says, "This is a man utterly lost indeed! Since he conducts himself so, what is there to choose between him and a brute? Why should I go to contend with a brute?"

'Thus it is that the superior man has a life-long anxiety and not one morning's calamity. As to what is matter of anxiety to him, that indeed be has. He says, "Shun was a man, and I also am a man. But Shun became an example to all the kingdom, and his conduct was worthy to be handed down to after ages, while I am nothing better than a villager."

'This indeed is the proper matter of anxiety to him. And in what way is he anxious about it? Just that he maybe like Shun: then only will he stop. As to what the superior man would feel to be a calamity, there is no such thing. He does nothing which is not according to propriety. If there should befall him one morning's calamity, the superior man does not account it a calamity.'
~ James Legge translation via nothingistic.org ~

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