Kao Tzŭ said, “Human nature may be compared with a block of wood; duty towards one's neighbour, with a wooden bowl. To develop charity and duty towards one's neighbour out of human nature is like making a bowl out of a block of wood.”
To this Mencius replied, “Can you without interfering with the natural constitution of the wood, make out of it a bowl? Surely you must do violence to that constitution in the process of making your bowl. And by parity of reasoning you would do violence to human nature in the process of developing charity and duty towards one’s neighbour. From which it follows that all men would come to regard these rather as evils than otherwise.”
Kao Tzŭ said, “Human nature is like rushing water, which flows east or west according as an outlet is made for it. For human nature makes indifferently for good or for evil, precisely as water makes indifferently for the east or for the west.”
Mencius replied, “Water will indeed flow indifferently towards the east or west; but will it flow indifferently up or down? It will not; and the tendency of human nature towards good is like the tendency of water to flow down. Every man has this bias towards good, just as all water flows naturally downwards. By splashing water, you may indeed cause it to fly over your head; and by turning its course you may keep it for use on the hillside; but you would hardly speak of such results as the nature of water. They are the results, of course, of a force majeure. And so it is when the nature of man is diverted towards evil.”
Kao Tzŭ said, “That which comes with life is nature.”
Mencius replied, “Do you mean that there is such a thing as nature in the abstract, just as there is whiteness in the abstract?”
“I do,” answered Kao Tzŭ.
“Just, for instance,” continued Mencius, “as the whiteness of a feather is the same as the whiteness of snow, or the whiteness of snow as the whiteness of jade?”
“I do,” answered Kao Tzŭ again.
“In that case,” retorted Mencius, “the nature of a dog is the same as that of an ox, and the nature of an ox the same as that of a man.”
Kao Tzŭ said, “Eating and reproduction of the species are natural instincts. Charity is subjective and innate; duty towards one’s neighbour is objective and acquired. For instance, there is a man who is my senior, and I defer to him as such. Not because any abstract principle of seniority exists subjectively in me, but in the same way that if I see a white man I recognise him as such, because he is so objectively to me. Consequently, I say that that duty towards one’s neighbour is objective or acquired.”
Mencius replied, “The cases are not analogous. The whiteness of a white horse is undoubtedly the same as the whiteness of a white man; but the seniority of a horse is not the same as the seniority of a man. Does our duty to our senior begin and end with the fact of his seniority? Or does it not rather consist in the necessity of deferring to him as such?”
Kao Tzŭ said, “I love my own brother; but I do not love another man's brother. The distinction arises from within myself; therefore I call it subjective or innate. But I defer to a stranger who is my senior just as I defer to a senior among my own people. The distinction comes to me from without; therefore I call it objective or acquired.”
Mencius retorted, “We enjoy food cooked by strangers just as much as food cooked by our own people. Yet extension of your principle lands us in the conclusion that our appreciation of cooked food is also objective and acquired.”