
Lesson · 4 min Stretch
Know It and Do It
In one line Two Neo-Confucians disagreed on how to learn the good, and agreed it must show in what you do.
Neo-Confucianism was a revival of Confucian thought in China, from about the eleventh century on. Two of its main voices were Zhu Xi, who lived in the twelfth century, and Wang Yangming, who came later.
Zhu Xi taught that a person learns the good by investigating things and affairs, to grasp the principle in each. Wang Yangming replied that the knowledge of the good is already in the mind, and that real knowing and acting are one. Wang borrowed Mencius’s picture of a child about to fall into a well: on his view, someone who feels no pull to help does not yet know compassion.
The two disagreed about where to look for the good, outside or within. Both held that learning without a change in conduct is incomplete, which is a useful test for anything you claim to know.
The ice on the step

Mara tells her class that she knows ice on a step is dangerous. The next morning she walks past the icy step outside her door and leaves it. A classmate says that she does not yet know it in the way that counts.
That afternoon she salts the step and warns the neighbors. She says she understands the lesson better when it is in her hands than when it is in her head.
Try this today Pick something you say you value and write one action this week that would show you mean it.
Cite or share this lesson
A plain reference you can paste into notes or an essay:
Quest2Reason. “Know It and Do It.” https://quest2reason.com/learn/lesson/know-it-and-do-it. Accessed 13 November 2026.
Sources
- Stanford Encyclopedia of Philosophy, “Wang Yangming” — Covers his teaching that knowing and acting are one.
- Stanford Encyclopedia of Philosophy, “Zhu Xi” — Covers his view that one learns by investigating things.
