来书云：「所释《大学》古本，谓致其本体之知，此固孟子『尽心』之旨，朱子亦以虚灵知觉为此心之量。然『尽心』由于『知性』，『致知』在于『格物』。」
「尽心由于知性，致知在于格物」，此语然矣。然而推本吾子之意，则其所以为是语者，尚有未明也。朱子以「尽心、知性、知天」为「物格、知致」，以「存心、养性、事天」为「诚意、正心、修身」，以「殀寿不贰、修身以俟」[1]为「知至仁尽、圣人之事」。若鄙人之见，则与朱子正相反矣。夫「尽心、知性、知天」者，生知、安行，圣人之事也；「存心、养性、事天」者，学知、利行，贤人之事也；「殀寿不贰，修身以俟」者，困知、勉行，学者之事也。岂可专以「尽心、知性」为知，「存心、养性」为行乎？吾子骤闻此言，必又以为大骇矣。然其间实无可疑者，一为吾子言之。
夫心之体，性也；性之原，天也。能尽其心，是能尽其性矣。《中庸》云：「惟天下至诚为能尽其性。」又云：「知天地之化育，质诸鬼神而无疑，知天也。」此惟圣人而后能然。故曰：「此生知、安行，圣人之事也。」
存其心者，未能尽其心者也，故须加存之之功；必存之既久，不待于存而自无不存，然后可以进而言尽。盖「知天」之「知」，如「知州」、「知县」之「知」，「知州」则一州之事皆己事也，「知县」则一县之事皆己事也，是与天为一者也；「事天」则如子之事父，臣之事君，犹与天为二也。天之所以命于我者，心也，性也，吾但存之而不敢失，养之而不敢害，如「父母全而生之，子全而归之」者也。故曰：「此学知、利行，贤人之事也。」
至于「殀寿不贰」，则与存其心者又有间矣。存其心者虽未能尽其心，固已一心于为善，时有不存，则存之而已；今使之「殀寿不贰」，是犹以殀寿贰其心者也；犹以殀寿贰其心，是其为善之心犹未能一也；存之尚有所未可，而何尽之可云乎？今且使之不以殀寿贰其为善之心，若曰「死生殀寿，皆有定命」，吾但一心于为善，修吾之身以俟天命而已，是其平日尚未知有天命也。「事天」虽与天为二，然已真知天命之所在，但惟恭敬奉承之而已耳；若「俟之」云者，则尚未能真知天命之所在，犹有所俟者也，故曰「所以立命」。立者「创立」之「立」，如「立德」、「立言」、「立功」、「立名」之类。凡言立者，皆是昔未尝有而今始建立之谓，孔子所谓「不知命，无以为君子」者也。故曰：「此困知、勉行，学者之事也。」
今以「尽心、知性、知天」为「格物、致知」，使初学之士尚未能不贰其心者，而遽责之以圣人生知、安行之事，如捕风捉影，茫然莫知所措其心，几何而不至于「率天下而路」也？今世致知、格物之弊亦居然可见矣。吾子所谓「务外遗内，博而寡要」者，无乃亦是过欤？此学问最紧要处，于此而差，将无往而不差矣。此鄙人之所以冒天下之非笑，忘其身之陷于罪戮，呶呶其言，其不容已者也。
来信说：「先生解释《大学》古本，说致其本体之知，这固然是孟子『尽心』的宗旨，朱子也以虚灵知觉为此心之量。然而『尽心』在于『知性』，『致知』在于『格物』。」
「尽心由于知性，致知在于格物」，这话是不错的。然而推究您的用意，说这话还有未明之处。朱子把「尽心、知性、知天」当作「物格、知至」，把「存心、养性、事天」当作「诚意、正心、修身」，把「夭寿不贰、修身以俟」当作「知至仁尽、圣人之事」。而依我的见解，恰与朱子相反。「尽心、知性、知天」是生知安行、圣人之事；「存心、养性、事天」是学知利行、贤人之事；「夭寿不贰、修身以俟」是困知勉行、学者之事。岂能专把「尽心知性」当作知、「存心养性」当作行呢？您骤然听到这话，必又以为骇人。然而其间实无可疑，让我为您一说。
心之体是性，性之本原是天。能尽其心，就是能尽其性了。《中庸》说：「惟天下至诚为能尽其性。」又说：「知天地之化育，质诸鬼神而无疑，知天也。」这只有圣人然后能做到，所以说这是生知安行、圣人之事。
存其心的人，是未能尽其心的人，所以必须加存养的功夫；必是存养得久了，不待存而自无不存，然后可以进而言尽。「知天」的知，如同知州、知县的知，知州则一州之事都是自己的事，知县则一县之事都是自己的事，这是与天合为一的；「事天」则如儿子侍奉父亲、臣子侍奉君主，还是与天为二。天所赋给我的，是心、是性，我只是存之不敢失、养之不敢害，如同「父母完整地生下我，我完整地归还父母」。所以说这是学知利行、贤人之事。
至于「夭寿不贰」，与存其心的人又有差距。存心的人虽未能尽其心，本已一心为善，偶有不存，存养回来就是了；如今要人「夭寿不贰」，是仍然拿夭寿贰其心的人；拿夭寿贰其心，说明为善之心还不能专一；存尚且做不到，谈什么尽呢？如今且要人不因夭寿而贰其为善之心，譬如说「死生夭寿都有定命」，我只是一心为善，修养自身以等待天命罢了——这说明他平日还不知有天命。「事天」虽与天为二，却已真知天命之所在，只是恭敬奉承罢了；至于说「俟」，是还不能真知天命所在，还在等待，所以叫「立命」。立是「创立」的立，如立德、立言、立功、立名之类。凡说立，都是从前未曾有而今才开始建立的意思，正是孔子所谓「不知命，无以为君子」。所以说这是困知勉行、学者之事。
如今把「尽心、知性、知天」当作「格物、致知」，让初学之士尚不能专一其心的人，一下子担起圣人生知安行之事，如同捕风捉影，茫然不知心往哪里放，怎能不至于「带着天下人疲于奔命」呢？当世致知格物之弊也显然可见了。您所谓「务外遗内、博而寡要」，恐怕也是这个过失吧？这是学问最紧要处，在这里错了，将无所不错。这就是我之所以冒天下人的非笑、忘掉自己身陷罪戮、喋喋不休而不能自已的缘故。
Your letter says: 'Your reading of the old text takes extending knowledge as extending the knowledge of the original substance — Mencius's aim of realizing the mind, and Zhu Xi too took the mind's empty numinous awareness as its measure. Yet realizing the mind rests on knowing nature; extending knowledge rests on investigating things.'
So far, right. Yet the intent behind your words remains unclear. Zhu Xi assigned realizing the mind, knowing nature, knowing Heaven to things investigated and knowledge extended; preserving the mind, nourishing nature, serving Heaven to sincerity, rectitude and self-cultivation; undivided by early death or long life, cultivating and awaiting, to knowledge complete and humaneness exhausted — the sage's affair. My view is the direct reverse. Realizing the mind, knowing nature, knowing Heaven belong to those born knowing who act at ease — the sage's affair; preserving the mind, nourishing nature, serving Heaven to learning and acting with advantage — the worthy's affair; undivided by lifespan, cultivating and awaiting, to knowing through hardship and acting through striving — the learner's affair. How can realizing and knowing be assigned to knowledge alone, preserving and nourishing to action alone? Hearing this you will be startled again; yet truly nothing in it is doubtful — let me state it.
The mind's substance is nature; nature's source is Heaven. To realize the mind fully is to realize nature fully. The Mean: only the utterly sincere can realize his nature; knowing Heaven-and-earth's transforming nourishment, tested before the spirits without doubt — this is knowing Heaven. Only the sage can do so — hence born knowing, acting at ease: the sage's affair.
To preserve the mind implies it is not yet fully realized; hence the work of preserving. Preserved long enough that preservation is no longer needed yet nothing unpreserved — only then may one speak of realizing. The knowing of knowing Heaven is the knowing of a prefect over his prefecture, a magistrate over his county: all its affairs one's own — one with Heaven. Serving Heaven is the son serving the father, the minister the ruler — still two with Heaven. What Heaven has conferred on me is mind and nature; I but preserve them, not daring to lose, nourish them, not daring to harm — as parents gave me whole and I return myself whole. Hence learning and advantage: the worthy's affair.
As to undivided by lifespan, that stands lower still than preserving the mind. The preserver, though not yet realizing, is already single-minded in good; when preservation lapses, he but returns to it. To bid one be undivided by lifespan is still to let lifespan divide the mind; divided, the heart for good is not yet single; not yet able even to preserve — what talk of realizing? Bid him not let lifespan divide his heart for good — 'death and life, early or late, are fixed by the Mandate; I am simply single-minded in good, cultivating myself and awaiting it' — that shows he does not yet know there is a Mandate. Serving Heaven, though two with Heaven, truly knows where the Mandate lies and but reverently attends it; 'awaiting' means not yet truly knowing where it lies, still waiting — hence 'establishing the Mandate'. Establish is found in establishing virtue, words, deeds, fame: what never was, now first set up — Confucius's not knowing the Mandate, one cannot be a noble person. Hence hardship and striving: the learner's affair.
To set realizing the mind, knowing nature, knowing Heaven as investigation and extension — charging beginners who cannot yet keep their hearts single with the born-knowing sage's task — is chasing wind and shadows, the mind nowhere to lodge, and cannot but lead the whole world running itself ragged. Today's defects in extension and investigation are plain to see. Your 'pursuing the outward, losing the inward; broad without essentials' — is it not this same fault? This is the most crucial point of learning: err here and there is no place one does not err. This is why I brave the world's ridicule, forget the perils to my person, and cannot hold my peace.
- 王本，「物格知致」作「物格知至」；「诚意正心修身」作「诚意正心」；「以殀寿不贰，修身以俟」作「以末节殀寿不贰，修身以俟」。