来书又云：「师云：『为学终身只是一事，不论有事无事，只是这一件。若说宁不了事，不可不加培养，却是分为两事也。』窃意觉精力衰弱，不足以终事者，良知也；宁不了事，且加休养，致知也。如何却为两事？若事变之来，有事势不容不了，而精力虽衰，稍鼓舞亦能支持，则持志以帅气可矣。然言动终无气力，毕事则困惫已甚，不几于暴其气已乎？此其轻重缓急，良知固未尝不知，然或迫于事势，安能顾精力？或因于精力，安能顾事势？如之何则可？」
「宁不了事，不可不加培养」之意，且与初学如此说，亦不为无益，但作两事看了，便有病痛在。孟子言必有事焉，则君子之学终身只是「集义」一事。义者，宜也，心得其宜之谓义。能致良知则心得其宜矣，故「集义」亦只是致良知。君子之酬酢万变，当行则行，当止则止，当生则生，当死则死，斟酌调停，无非是致其良知，以求自慊而已。故「君子素其位而行」，「思不出其位」，凡谋其力之所不及，而强其知之所不能者，皆不得为致良知；而凡「劳其筋骨，饿其体肤，空乏其身，行拂乱其所为，动心忍性以增益其所不能」者，皆所以致其良知也。若云宁不了事，不可不加培养者，亦是先有功利之心，计较成败利钝而爱憎取舍于其间。是以将了事自作一事，而培养又别作一事，此便有是内、非外之意，便是自私用智，便是「义外」，便有「不得于心勿求于气」之病，便不是致良知以求自慊之功矣。所云「鼓舞支持，毕事则困惫已甚」，又云「迫于事势，困于精力」，皆是把作两事做了，所以有此。凡学问之功，一则诚，二则伪，凡此皆是致良知之意欠诚一真切之故。《大学》言：「诚其意者，如恶恶臭，如好好色，此之谓自慊。」曾见有恶恶臭，好好色，而须鼓舞支持者乎？曾见毕事则困惫已甚者乎？曾有迫于事势，困于精力者乎？此可以知其受病之所从来矣。
来信又说：「老师说：『为学终身只是一事，不论有事无事，只是这一件。若说宁不了事、不可不加培养，却是分为两事了。』我私下觉得，觉精力衰弱、不足以终事的，是良知；宁不了事、且加休养，是致知。怎么却是两事？若事变之来，有事势不容不了，而精力虽衰，稍加鼓舞也能支撑，那是持志以帅气就行了。然而言动终无气力，办完事便困惫不堪，这不近于暴其气吗？这中间的轻重缓急，良知固然未尝不知；但或迫于事势，怎能顾精力？或困于精力，怎能顾事势？怎么办才好？」
「宁不了事，不可不加培养」这话，姑且对初学的人这样说，也不为无益；但作两事看了，便有病痛在。孟子讲「必有事焉」，那么君子之学终身只是「集义」一事。义就是宜，心得其宜叫作义。能致良知则心得其宜了，所以「集义」也只是致良知。君子酬酢万变，当行则行、当止则止、当生则生、当死则死，斟酌调停，无非是致其良知，以求自慊而已。所以「君子素其位而行」「思不出其位」。凡是谋划力所不及、强求知所不能的，都算不得致良知；而凡「劳其筋骨，饿其体肤，空乏其身，行拂乱其所为，动心忍性以增益其所不能」的，都是所以致其良知。至于说宁不了事、不可不加培养，也是先有功利之心，计较成败利钝而在其间爱憎取舍。于是把办事自己看作一事，培养又另看作一事，这便有是内非外之意，便是自私用智，便是「义外」，便有「不得于心勿求于气」的病，便不是致良知以求自慊的功夫了。所说「鼓舞支持，毕事则困惫已甚」，又说「迫于事势，困于精力」，都是把作两事做了，所以有这些。凡学问之功，一则是诚，二则是伪；这些都是致良知之意欠诚一真切的缘故。《大学》说：「诚其意者，如恶恶臭，如好好色，此之谓自慊。」可曾见过恶恶臭、好好色还需要鼓舞支持的？可曾见过办完事困惫不堪的？可曾见过迫于事势、困于精力的？由此可以知道病根的由来了。
Your letter further says: 'You said learning is lifelong one affair — affairs or none, this one thing; to say rather leave the affair undone than stint the nurturing is to make two. Yet to feel one's strength failing short of the affair — that is innate knowledge; rather leave it undone and rest — that is extension. How two? And when change drives in and the affair brooks no delay, strength flagging yet a little rallying suffices to carry on — hold the will to marshal the energies. But speech and motion lack all force, and the affair done, exhaustion is utter — is that not abusing one's energies? The weights and urgencies innate knowledge surely knows; yet pressed by circumstance, how mind one's strength? Sapped of strength, how mind circumstance? What is best?'
The saying rather-leave-undone-than-stint-nurturing, told to beginners, is not without use; taken as two things, the defect enters. Mencius's always-having-the-task makes the noble person's lifelong learning one affair only: accumulating rightness. Rightness is fitness: the mind finding its fit. Extending innate knowledge, the mind finds its fit — hence accumulating rightness is only extending innate knowledge. The noble person amid ten thousand changes: move when to move, stop when to stop, live when to live, die when to die — weighing and adjusting, all of it extending innate knowledge for self-content alone. Hence the noble person does what is proper to the station, and thought strays not beyond it. All scheming beyond one's strength and forcing beyond one's knowing fail to be extending innate knowledge; while all that taxes the sinews, starves the body, empties the self, confounds the doings — stirring the mind, steeling the nature, to increase what one cannot — is precisely extending innate knowledge. As for rather-leave-undone-than-stint-nurturing: there too a calculating heart of profit and loss runs first, weighing success and failure, love and hate, taking and leaving — so finishing affairs becomes one thing and nurturing another. That is approving the inner and condemning the outer, wit in selfishness, rightness made external, the sickness of failing-in-the-heart yet seeking-not-in-the-energies — no longer the work of extending innate knowledge toward self-content. Your rallying to carry through and collapsing after; your pressed by circumstance, sapped of strength — all from doing it as two things. In the work of learning, one is sincerity, two is pretense; all this is the intent of extension wanting singleness and earnestness. The Great Learning: making the intention sincere is hating a stench as a stench, loving beauty as beauty — this is self-content. Ever see one who hates a stench or loves beauty needing to rally and prop himself? Ever see him collapse when done? Pressed by circumstance, sapped of strength? From this the seat of the disease may be known.