In addition to his carefully curated commentaries on the Four Books, we find each passage discussed extensively with his students in the Collected Conversations of Master Zhu (zhuzi yulei 朱子語類). These conversations are invaluable in ascertaining the precise meaning of the commentaries, and reveal other insights.
Youzi said: As for one's acts as a human: One who is an obedient son and respectful brother, and yet likes defying superiors—rare! One who doesn’t like defying superiors, and yet likes raising rebellion—has never this been. The noble man focuses efforts on the root; when the root is established the Way will grow lifelong. That which family affection and brotherly respect are, they act as humanity's root?
有子曰：「其為人也孝弟，而好犯上者，鮮矣；不好犯上，而好作亂者，未之有也。君子務本，本立而道生。孝弟也者，其為仁之本與！」
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Yulei ch. 20, Lunyu 1:2, 20
Question on “family affection and brotherly respect act as the root of humanity.”
Answer: This is about putting the way of humanity into practice. It is akin to the ‘humanity’ in “implementing governance with humanity” (Mengzi 1A:7) and distinct from the ‘humanity’ in “to master oneself and return to propriety is humanity” (Lunyu 12:1). Thus Cheng Yi referred to it as “acting with humanity” (xingren 行仁, humanity in one’s conduct). For those learning to practice humanity, it is about holding just this one thought in mind, and from there, this humanity emerges. Yet it all hinges on the same principle: here, “the root of practicing humanity” (weiren zhi ben 為仁之本) is discussed in terms of actions (shi 事, real matters), while “to master oneself and return to propriety” (kiji fuli 克己復禮) is discussed in terms of the mind (xin 心, the heartmind and the will).
Further discussion on the word “root”: It aligns with the idea in the Great Learning that “There is never a case when the root is in disorder and yet the branches are in order.” Principle is one but its manifestations are many—although valuing all equally is noble, if it does not begin with loving one’s own kin, it is not attainable.
問「孝弟為仁之本」。曰：「此是推行仁道，如『發政施仁』之『仁』同，非『克己復禮為仁』之『仁』，故伊川謂之『行仁』。學者之為仁，只一念相應便是仁。然也只是這一箇道理。『為仁之本』，就事上說；『克己復禮』，就心上說。」又論「本」字云：「此便只是大學『其本亂而末治者否矣』意思。理一而分殊，雖貴乎一視同仁，然不自親始，也不得。」
Comment: This passage makes the intention behind the Collected Commentaries perfectly clear. There is the root of humanity, as in the mind, its essence (ti 體), and there is the root of humanity, as in practice, its application (yong 用). It is certainly noble to value both, but the Confucian method focuses on what can concretely be done. Hence Teacher Zhu’s focus of this verse on humane conduct as a habit, not merely a state of mind. See also passage #71, where he reiterates not making it about mere knowing of humanity.
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Yulei ch. 20, Lunyu 1:2, 71:
The Confucian tradition only speaks of practicing humanity, not of [intellectually] knowing humanity.
聖門只說為仁，不說知仁。
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