问：「知识不长进，如何？」
先生曰：「为学须有本原，须从本原上用力，渐渐『盈科而进』。仙家说婴儿，亦善譬。婴儿在母腹时，只是纯气，有何知识？出胎后，方始能啼，既而后能笑，又既而后能认识其父母兄弟，又既而后能立、能行、能持、能负，卒乃天下之事无不可能。皆是精气日足，则筋力日强，聪明日开，不是出胎日便讲求推寻得来。故须有个本原。圣人到『位天地，育万物』也只从『喜怒哀乐未发之中』上养来。后儒不明格物之说，见圣人无不知、无不能；便欲于初下手时讲求得尽，岂有此理？」
又曰：「立志用功，如种树然。方其根芽，犹未有；及其有干，尚未有枝；枝而后叶，叶而后花实。初种根时，只管栽培灌溉；勿作枝想，勿作叶想，勿作花想，勿作实想。悬想何益？但不忘栽培之功，怕没有枝、叶、花、实？」
有人问：「知识不长进，怎么办？」
先生说：「为学必须有个本原，必须从本原上用力，渐渐地『盈科而后进』。仙家讲婴儿，也是个好比喻。婴儿在母腹中时，只是纯气，有什么知识？出生后，才会啼哭，继而会笑，再继而能认识父母兄弟，再进而能站、能走、能拿、能负重，最后天下的事没有不能做的。这都是精气日益充足，筋力日益强健，聪明日益开发，不是出胎那一天就讲求推究得来的。所以必须有个本原。圣人达到『安排天地、化育万物』，也只是从『喜怒哀乐未发之中』上养出来的。后世儒者不明白格物之说，见圣人无所不知、无所不能，便想在下手的初讲求个穷尽，哪有这个道理？」
又说：「立志用功，就像种树。刚种下根芽时，还没有干；有了干，还没有枝；有枝然后有叶，有叶然后开花结果。初种根时，只管栽培灌溉，不要去想枝，不要想叶，不要想花，也不要想果。空想有什么用？只要不忘记栽培的功夫，还怕没有枝叶花果吗？」
Someone asked: "My knowledge does not advance — what to do?"
The Master said: "Learning must have a root-source; work must be done at that source, advancing gradually as water fills each hollow before flowing on. The immortals' image of the infant is a fine figure. In the womb the infant is pure vital breath — what knowledge has it? Born, it can first cry, then smile, then recognize parents and brothers, then stand, walk, grasp, carry, until at last nothing under heaven is beyond it. All this comes as essence and breath daily fill, sinews daily strengthen, intelligence daily opens — not from study pressed through on the day of birth. So there must be a root-source. Even the sage's 'setting heaven and earth in place and nurturing the ten thousand things' was cultivated from 'the equilibrium before joy, anger, sorrow and pleasure are aroused.' Later scholars, mistaking the doctrine of investigating things and seeing the sage knew all and could do all, try to exhaust everything at the very start of study — what sense is there in that?"
He added: "Setting the will and working at it is like planting a tree. At the sprout there is not yet a trunk; with the trunk, not yet branches; branches, then leaves; leaves, then blossom and fruit. When the root is first planted, just cultivate and water — do not think of branches, nor leaves, nor blossom, nor fruit. What good is idle imagining? Only do not forget the work of tending, and will you fear to lack branches, leaves, blossom and fruit?"