Mencius - Book 2, Part 1, Chapter 2A

Kung-sun Ch'âu asked Mencius, saying, 'Master, if you were to be appointed a high noble and the prime minister of Ch'î, so as to be able to carry your principles into practice, though you should thereupon raise the ruler to the headship of all the other princes, or even to the royal dignity, it would not be to be wondered at. In such a position would your mind be perturbed or not?' Mencius replied, 'No. At forty, I attained to an unperturbed mind.'

Ch'âu said, 'Since it is so with you, my Master, you are far beyond Mang Pan.' 'The mere attainment,' said Mencius, 'is not difficult. The scholar Kâo had attained to an unperturbed mind at an earlier period of life than I did.'

Ch'âu asked, 'Is there any way to an unperturbed mind?' The answer was, 'Yes.

'Pî-kung Yû had this way of nourishing his valor: He did not flinch from any strokes at his body. He did not turn his eyes aside from any thrusts at them. He considered that the slightest push from any one was the same as if he were beaten before the crowds in the market-place, and that what he would not receive from a common man in his loose large garments of hair, neither should he receive from a prince of ten thousand chariots. He viewed stabbing a prince of ten thousand chariots just as stabbing a fellow dressed in cloth of hair. He feared not any of all the princes. A bad word addressed to him be always returned.
~ James Legge translation via nothingistic.org ~

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