Zhu Xi's interpretation of investigation is forced and not the sage's intent.
"Zhu Xi's interpretation of investigation is forced and not the sage's intent."
爱问：「格物之说，如先生所教，明白简易，人人见得。朱子聪明，何故反有不知？」
先生曰：「朱子格物之训，未免牵合附会，非圣人之旨。朱子尝以『格物』为『穷至事物之理』，又训『格』为『至』。如以『至』训，则于『致知』之义不通。盖『致知』者，致吾心之良知也。若以『至物』为义，则致知亦当云『至知』矣。且即以穷理言之，理在心而不在物。若穷事物之理，岂能穷得尽？天下事物无穷，安能一一穷得？」
Xu Ai asked: "Regarding the theory of investigation, as you teach it, it is clear and simple, and everyone can understand it. Zhu Xi was so intelligent — why did he not understand this?"
The Master said: "Zhu Xi's interpretation of investigation is forced and not the sage's intent. Zhu Xi once defined 'investigation of things' as 'exhaustively reaching the principle of things,' and also glossed 'ge' as 'to reach.' If we take 'to reach' as the meaning, then it does not work with 'extending knowledge.' For extending knowledge means extending the innate knowledge of my mind. If 'reaching things' is the meaning, then extending knowledge should also be called 'reaching knowledge.' Moreover, speaking of exhausting principle — principle is in the mind, not in things. If one tries to exhaust the principles of things, how can one ever finish? The things of the world are infinite — how can one exhaust them all?"
In the age of information overload, Zhu Xi's approach of "exhaustively studying the principles of things" can lead to analysis paralysis. Yangming reminds us: start with the mind's innate knowledge, then learn what truly matters — not trying to learn everything.
"Zhu Xi once defined 'investigation of things' as 'exhaustively reaching the principle of things.'"
Yangming critiques Zhu Xi from a训诂 (philological) perspective: if "ge" means "to reach things," then "investigating things" means "going to things" — but "extending knowledge" would then need to be called "reaching knowledge," which doesn't make sense. The two phrases should use "ge" and "zhi" in parallel.
"Principle is in the mind, not in things."
This is the fundamental disagreement between Yangming and Zhu Xi. Zhu Xi holds that principle exists objectively in things; Yangming holds that principle is in the mind. This is not just a philosophical difference but leads to completely different cultivation methods.