"If we say that something exists or does not exist, in deference to the function it fulfils or does not fulfil, then there is nothing which does not exist, nothing which does exist. To know that east and west are convertible and yet necessary terms,—this is the due adjustment of functions. "If we say that anything is good or evil because it is either good or evil in our eyes, then there is nothing which is not good, nothing which is not evil. To know that Yao and Chieh were both good and both evil from their opposite points of view,—this is the expression of a standard. "Of old Yao abdicated in favour of Shun, and the latter ruled. Kuei abdicated in favour of Chih, and the latter failed. T'ang and Wu got the empire by fighting. By fighting, Poh Kung lost it. From which it may be seen that the rationale of abdicating or fighting, of acting like Yao or like Chieh, must be determined according to the opportunity, and may not be regarded as a constant quantity. "A battering-ram can knock down a wall, but it cannot repair the breach. Different things are differently applied. "Ch'ih-Chi and Hua Liu could travel 1,000 li in one day, but for catching rats they were not equal to a wild cat. Different animals possess different aptitudes.

All in the world know the beauty of the beautiful, and in doing this they have (the idea of) what ugliness is; they all know the skill of the...