爱问：「先生以『博文』为『约礼』功夫；深思之，未能得。略请开示。」
先生曰：「『礼』字即是『理』字。『理』之发见可见者，谓之『文』；『文』之隐微不可见者，谓之『理』；只是一物。『约礼』，只是要此心纯是一个天理。要此心纯是天理，须就『理』之发见处用功。如发见于事亲时，就在事亲上学存此天理；发见于事君时，就在事君上学存此天理；发见于处富贵、贫贱时，就在处富贵、贫贱上学存此天理；发见于处患难、夷狄时，就在处患难、夷狄上学存此天理。至于作止、语默，无处不然。随他发见处，即就那上面学个存天理。这便是『博学之于文』，便是『约礼』的功夫。『博文』即是『惟精』，『约礼』即是『惟一』。」
徐爱问：「先生把『博文』看作『约礼』的功夫，我深思之后未能明白，请先生开示。」
先生说：「『礼』字就是『理』字。理的发见可见的部分叫作『文』，文的隐微不可见的本体叫作『理』，只是一个物。『约礼』，只是要此心纯是一个天理。要此心纯是天理，就必须在理的发见处用功。如发见于侍奉双亲时，就在侍奉双亲上学存此天理；发见于侍奉君主时，就在侍奉君主上学存此天理；发见于身处富贵贫贱时，就在富贵贫贱上学存此天理；发见于身陷患难、居于夷狄时，就在患难夷狄上学存此天理。至于行动静止、说话沉默，无处不是如此。随着它发见的地方，就在那上面学个存天理，这便是『博学之于文』，便是『约礼』的功夫。『博文』就是『惟精』，『约礼』就是『惟一』。」
Xu Ai asked: "You take 'pursuing culture broadly' as the work of 'restraining oneself with ritual'; thinking it over I do not grasp it. Please enlighten me."
The Master said: "'Ritual' is 'principle'. Where principle manifests visibly, it is called 'culture'; the hidden, invisible substance of culture is called 'principle' — one and the same thing. 'Restraining oneself with ritual' means making this mind purely heavenly principle. To make it purely heavenly principle, one must work wherever principle manifests: in serving parents, learn to preserve this heavenly principle there; in serving a ruler, there; in wealth, poverty, nobility or lowliness, there; in hardship or among foreign peoples, there. In activity and rest, speech and silence, nowhere is it otherwise. Wherever it manifests, learn right there to preserve heavenly principle — this is 'learning broadly from culture', the work of 'restraining with ritual'. 'Broad culture' is 'refinement'; 'restraint by ritual' is 'unity'."