梁日孚问：「居敬、穷理是两事，先生以为一事，何如？」
先生曰：「天地间只有此一事，安有两事？若论万殊，礼仪三百，威仪三千，又何止两？公且道居敬是如何？穷理是如何？」
曰：「居敬是存养工夫，穷理是穷事物之理。」
曰：「存养个甚？」
曰：「是存养此心之天理。」
曰：「如此，亦只是穷理矣。」曰：「且道如何穷事物之理？」
曰：「如事亲便要穷孝之理，事君便要穷忠之理。」
曰：「忠与孝之理，在君、亲身上？在自己心上？若在自己心上，亦只是穷此心之理矣。且道如何是敬？」
曰：「只是主一。」
「如何是主一？」
曰：「如读书，便一心在读书上；接事，便一心在接事上。」
曰：「如此则饮酒，便一心在饮酒上；好色，便一心在好色上。却是逐物，成甚居敬工夫？」
日孚请问。
曰：「一者，天理。主一是一心在天理上。若只知主一，不知一即是理，有事时便是逐物，无事时便是著空。惟其有事无事，一心皆在天理上用功，所以居敬亦即是穷理。就穷理专一处说，便谓之居敬；就居敬精密处说，便谓之穷理。却不是居敬了，别有个心穷理；穷理时，别有个心居敬：名虽不同，功夫只是一事。就如《易》言『敬以直内，义以方外』，敬即是无事时义，义即是有事时敬，两句合说一件。如孔子言『修己以敬』，即不须言义；孟子言『集义』，即不须言敬。会得时，横说竖说，工夫总是一般。若泥文逐句，不识本领，即支离决裂，工夫都无下落。」
问：「穷理何以即是尽性？」
曰：「心之体，性也；性即理也。穷仁之理，真要仁极仁；穷义之理，真要义极义：仁、义只是吾性，故穷理即是尽性。如孟子说『充其恻隐之心』，至『仁不可胜用』，这便是穷理工夫。」
日孚曰：「先儒谓『一草一木亦皆有理，不可不察。』，如何？」
先生曰：「夫我则不暇。公且先去理会自己性情，须能尽人之性，然后能尽物之性。」日孚悚然有悟。
梁日孚问：「居敬、穷理是两件事，先生认为是一件事，为什么？」
先生说：「天地间只有这一件事，哪有两件？若论万殊，礼仪三百、威仪三千，又何止两件？您且说说居敬是怎样的？穷理是怎样的？」
答：「居敬是存养的功夫，穷理是穷究事物的道理。」
问：「存养个什么？」
答：「是存养此心的天理。」
说：「这样，也就是穷理了。且说怎样穷事物之理？」
答：「如事奉双亲便要穷孝的理，事奉君主便要穷忠的理。」
说：「忠与孝的理，在君亲身上？还是在自己心上？若在自己心上，也只是穷此心之理了。且说什么 是敬？」
答：「只是主一。」
「什么是主一？」
答：「如读书，便一心在读书上；接事，便一心在接事上。」
说：「这样，饮酒便一心在饮酒上，好色便一心在好色上，却是追逐外物，算什么居敬功夫？」
日孚请教。
先生说：「一，就是天理。主一是一心在天理上。若只知主一，而不知一就是理，有事时便是逐物，无事时便是着空。正因为有事无事，一心都在天理上用功，所以居敬也就是穷理。就穷理的专一处说，便叫居敬；就居敬的精密处说，便叫穷理。并不是居敬之后，另有一个心去穷理；穷理时，另有一个心去居敬：名称虽不同，功夫只是一件事。就像《易》说『敬以直内，义以方外』，敬就是无事时的义，义就是有事时的敬，两句合说一件事。孔子说『修己以敬』，就不必再说义；孟子说『集义』，就不必再说敬。领会得时，横说竖说，功夫总是一样。若拘泥文句、不识根本，便支离决裂，功夫都无落点。」
问：「穷理为什么就是尽性？」
答：「心之体是性，性就是理。穷仁之理，真要仁到极仁；穷义之理，真要义到极义：仁义只是我的性，所以穷理就是尽性。如孟子说『扩充恻隐之心』，直到『仁用之不尽』，这便是穷理的功夫。」
日孚说：「先儒说『一草一木也都有理，不可不察』，怎么样？」
先生说：「我可没这闲工夫。您且先去理会自己的性情，必须能尽人之性，然后才能尽物之性。」日孚悚然有悟。
Liang Rifu asked: 'Reverent composure and exhausting principle are two things; you hold them one — how?'
The Master said: 'Under heaven and earth there is only this one thing — where are two? Count the differences: three hundred rites, three thousand rules — far more than two. Tell me, what is reverent composure? What is exhausting principle?'
'Composure is the work of preserving and nourishing; exhausting principle is exhausting the principles of things and affairs.'
'Preserving what?'
'Preserving this mind's heavenly principle.'
'Then that is already exhausting principle. And how does one exhaust the principles of things?'
'Serving parents, exhaust the principle of filial piety; serving a ruler, that of loyalty.'
'Is the principle of loyalty and filial piety on the ruler's and parents' bodies, or in your own mind? If in your own mind, then it is only exhausting this mind's principle. And what is reverence?'
'Only abiding in the one.'
'What is abiding in the one?'
'Reading, the whole mind on reading; handling affairs, the whole mind on them.'
'Then drinking, the whole mind on drinking; lusting, the whole mind on lust — chasing things: what composure is that?'
Rifu begged instruction.
The Master said: 'The one is heavenly principle; abiding in the one is the whole mind on heavenly principle. Know only abiding-in-one without knowing the one is principle, and amid affairs you chase things, without affairs you sit in vacancy. Because with affairs or without, the whole mind works at principle, reverent composure is exhausting principle. Spoken of as the single-pointedness of exhausting principle, it is called composure; as its fine-grained precision, it is called exhausting principle. It is not that after composure another mind exhausts principle, nor while exhausting principle another mind keeps composure: the names differ, the work is one thing. As the Changes says, reverence straightens the within, rightness squares the without: reverence is rightness without affairs; rightness is reverence amid affairs — two phrases, one matter. Confucius said cultivating oneself by reverence — no need to add rightness; Mencius said accumulating rightness — no need to add reverence. Grasp it, and said any way at all, the work is the same. Cleave to phrases without knowing the root, and it shatters into fragments with nowhere to land.'
'Why is exhausting principle fulfilling one's nature?'
'The mind's substance is nature; nature is principle. Exhaust the principle of humaneness until humaneness is utterly humane; of rightness until rightness is utterly right: humaneness and rightness are just my nature — so exhausting principle is fulfilling nature. As when Mencius speaks of expanding the compassionate heart till humaneness is inexhaustible — that is the work of exhausting principle.'
Rifu said: 'Earlier scholars said even each grass and tree has its principle and must be examined. What of that?'
The Master said: 'For me there is no such leisure. First attend to your own nature and feelings: only able to fulfill human nature can one fulfill the natures of things.' Rifu started into awakening.