问：「古人论性，各有异同，何者乃为定论？」
先生曰：「性无定体，论亦无定体。有自本体上说者，有自发用上说者，有自源头上说者，有自流弊处说者。总而言之，只是一个性，但所见有浅深尔。若执定一边，便不是了。性之本体，原是无善、无恶的。发用上也原是可以为善、可以为不善的。其流弊也原是一定善、一定恶的。譬如眼，有喜时的眼，有怒时的眼，直视就是看的眼，微视就是觑的眼。总而言之，只是这个眼。若见得怒时眼，就说未尝有喜的眼；见得看时眼，就说未尝有觑的眼，皆是执定，就知是错。孟子说性，直从源头上说来，亦是说个大概如此。荀子性恶之说，是从流弊上说来，也未可尽说他不是，只是见得未精耳。众人则失了心之本体。」
问：「孟子从源头上说性，要人用功在源头上明彻；荀子从流弊说性，功夫只在末流上救正，便费力了。」
先生曰：「然。」
问：「古人论性各有异同，哪一种才是定论？」
先生说：「性没有定体，论也没有定体。有从本体上说的，有从发用上说的，有从源头上说的，有从流弊处说的。总而言之只是一个性，只是所见有浅深罢了。若执着一边，便错了。性的本体，原是无善无恶的；发用上原是可以为善、可以为不善的；到流弊处原是一定善、一定恶的。譬如眼睛：有喜时的眼，有怒时的眼，直视是看的眼，微视是觑的眼，总而言之只是这个眼。若见到怒时的眼，就说未尝有喜的眼；见到看时的眼，就说未尝有觑的眼，都是执着一边，就知道错了。孟子说性，直接从源头上说来，也只是说个大概如此；荀子性恶之说，是从流弊上说来，也不能全说他不对，只是见得未精。众人则是失了心的本体。」
问：「孟子从源头上说性，是让人把功夫用在源头上明彻；荀子从流弊上论性，功夫只在末流上救正，便费力了。」
先生说：「是的。」
Asked: 'The ancients differed on nature — which is the settled doctrine?'
The Master said: 'Nature has no fixed substance; its doctrines none either. Some speak from the substance, some from the working, some from the source, some from the degenerate flow. All said, one nature only — the sights differ merely in depth. Cling to one side and you err. Nature's substance is of itself neither good nor evil; in its working it can turn good or evil; in its degenerate flow it is fixedly good or fixedly evil. Like the eye: a joyful eye, an angry eye; the straight gaze is seeing, the sidelong is peering — one eye all the same. See the angry eye and say there never was a joyful one; the seeing eye and deny the peering one — each is clinging to one side, plainly wrong. Mencius spoke of nature straight from the source, in outline; Xunzi's nature-evil spoke from the degenerate flow — not wholly mistaken, only unrefined in sight. The crowd simply lose the mind's substance.'
'So Mencius' source-speech sets the work at the source, clear through; Xunzi's sets it repairing the tail-waters — laborious.'
'It is so.'