希渊问：「圣人可学而至，然伯夷、伊尹于孔子才力终不同，其同谓之圣者安在？」
先生曰：「圣人之所以为圣，只是其心纯乎天理，而无人欲之杂。犹精金之所以为精，但以其成色足而无铜铅之杂也。人到纯乎天理方是圣，金到足色方是精。然圣人之才力，亦有大小不同，犹金之分两有轻重。尧、舜犹万镒，文王、孔子犹九千镒，禹、汤、武王犹七八千镒，伯夷、伊尹犹四五千镒。才力不同，而纯乎天理则同，皆可谓之圣人；犹分两虽不同，而足色则同，皆可谓之精金。以五千镒者而入于万镒之中，其足色同也；以夷、尹而厕之尧、孔之间，其纯乎天理同也。盖所以为精金者，在足色，而不在分两；所以为圣者，在纯乎天理，而不在才力也。故虽凡人而肯为学，使此心纯乎天理，则亦可为圣人；犹一两之金比之万镒，分两虽悬绝，而其到足色处，可以无愧。故曰『人皆可以为尧、舜』者以此。学者学圣人，不过是去人欲而存天理耳；犹炼金而求其足色。金之成色所争不多，则锻炼之工省而功易成；成色愈下，则锻炼愈难。人之气质清浊粹驳，有中人以上、中人以下；其于道，有生知安行、学知利行；其下者必须人一己百，人十己千：及其成功则一。后世不知作圣之本是纯乎天理，却专去知识、才能上求圣人。以为圣人无所不知、无所不能，我须是将圣人许多知识、才能逐一理会始得。故不务去天理上著工夫，徒弊精竭力，从册子上钻研、名物上考索、形迹上比拟，知识愈广而人欲愈滋，才力愈多而天理愈蔽。正如见人有万镒精金，不务锻炼成色，求无愧于彼之精纯，而乃妄希分两，务同彼之万镒，锡、铅、铜、铁杂然而投，分两愈增而成色愈下，既其梢末，无复有金矣。」
时曰仁在傍，曰：「先生此喻足以破世儒支离之惑，大有功于后学。」
先生又曰：「吾辈用功，只求日减，不求日增。减得一分人欲，便是复得一分天理。何等轻快脱洒？何等简易？」
希渊问：「圣人可以学而至，但伯夷、伊尹与孔子在才力上终究不同，同样称为圣人的依据在哪里？」
先生说：「圣人之所以为圣，只是他的心纯乎天理，没有人欲的夹杂。就像精金之所以为精，只因成色足而没有铜铅的夹杂。人到了纯乎天理才是圣，金到了足色才是精。但圣人的才力也有大小不同，如同金的分量有轻重。尧舜如同万镒，文王孔子如同九千镒，禹汤武王如同七八千镒，伯夷伊尹如同四五千镒。才力不同，而纯乎天理相同，都可称为圣人；就像分量虽不同，而足色相同，都可谓精金。把五千镒的金放在万镒之中，它们的足色相同；把夷尹放在尧孔之间，他们纯乎天理相同。精金之所以为精，在足色而不在分量；圣人之所以为圣，在纯乎天理，而不在才力。所以即使是凡人，只要肯为学，使此心纯乎天理，也可以成为圣人；就像一两的金比起万镒，分量虽悬殊，而到了足色的地步，可以无愧。所以说『人皆可以为尧舜』，就是这个意思。学者学圣人，不过是去人欲、存天理罢了，如同炼金求其足色。金的成色本相差不多，锻炼的功夫就省而容易成功；成色越差，锻炼越难。人的气质有清浊纯杂，有中人以上、中人以下；对道来说，有生知安行、学知利行；最下的必须别人一分自己百分、别人十分自己千分：到成功时则是一样的。后世不知道作圣的根本是纯乎天理，却专从知识才能上求圣人，以为圣人无所不知、无所不能，我必须把圣人那许多知识才能一一理会才行。所以不在天理上下功夫，只是耗尽精力，从册子上钻研、名物上考索、形迹上比拟，知识越广而人欲越滋长，才力越多而天理越受蒙蔽。正如见人有万镒精金，不在锻炼成色上求无愧于他的精纯，却妄想增加分量，务求等同他的万镒，把锡铅铜铁杂七杂八投进去，分量越增而成色越低，到头来，就再没有金子了。」
当时徐爱在旁边说：「先生这个比喻足以破除世俗儒者支离的迷惑，对后学大有功劳。」
先生又说：「我们用功，只求日日减损，不求日日增加。减得一分人欲，便是复得一分天理。何等轻快洒脱？何等简易？」
Xiyuan asked: 'The sage can be reached by learning — yet Bo Yi and Yi Yin finally differed from Confucius in talent; on what ground are all called sages?'
The Master said: 'The sage is a sage only through a mind pure in heavenly principle without any mixture of selfish desire — as refined gold is refined only by full fineness unalloyed with copper or lead. Man become pure in principle is sage; gold reaching full fineness is refined. Yet sages' talents differ in size, as gold differs in weight: Yao and Shun ten thousand yi, King Wen and Confucius nine thousand, Yu, Tang and King Wu seven or eight thousand, Bo Yi and Yi Yin four or five thousand. Talents differ; purity in heavenly principle is the same — all may be called sages; as weights differ yet fineness is one, all may be called refined gold. Set the five-thousand-yi gold among the ten-thousand and the fineness matches; set Yi and Yin between Yao and Confucius and their purity in principle matches. Gold is refined by fineness, not weight; the sage is sage by purity of principle, not by talent. So even an ordinary person, if he will learn and make this mind pure in heavenly principle, may become a sage — like one ounce of gold against ten thousand yi: the weight is worlds apart, yet at full fineness it need yield to none. Hence: everyone can become a Yao or a Shun. Learning to be a sage is nothing but removing human desire and preserving heavenly principle — refining gold to full fineness. Gold near-fine needs little smelting and is easily perfected; the baser the ore, the harder the smelting. Men's endowments are clear or turbid, pure or mixed — above the mean, below the mean; some know at birth and act with ease, some learn and act with advantage; the lowest must give a hundredfold where others give one, a thousandfold where others give ten — yet at success all are one. Later ages, not knowing the root of sagehood is purity in principle, sought sages in knowledge and ability, thinking: the sage knows all and can all, so I must item by item master the sage's knowledge and talents. So instead of working at principle, they exhaust themselves burrowing in books, hunting names and measures, comparing outward traces — knowledge ever wider and desire ever fatter, talents ever more and principle ever more veiled. It is like seeing a man's ten-thousand-yi refined gold and, instead of smelting for a fineness that shames not his purity, vainly dreaming of matching his weight, throwing in tin, lead, copper and iron pell-mell: the weight grows and the fineness falls, till at the end no gold remains.'
Xu Ai, at his side, said: 'This figure is enough to break the later scholars' maze of fragments — a great service to learners.'
The Master added: 'Our work asks only daily subtraction, never daily addition. Subtract one part of human desire and you recover one part of heavenly principle. How light and free! How simple!'