尽心上 · 第 21 / 46 章 · 孟子 7A.21
《孟子·尽心上》7A.21：仁义礼智根于心
孟子指出，广土众民、定四海固然可欲，但君子之性不在那里；真正的根在心中生长的仁义礼智，并会外溢到面貌、背脊与四体。
孟子曰：「广土众民，君子欲之，所乐不存焉。中天下而立，定四海之民，君子乐之，所性不存焉。君子所性，虽大行不加焉，虽穷居不损焉，分定故也。君子所性，仁义礼智根于心。其生色也，睟然见于面、盎于背。施于四体，四体不言而喻。」
英文参考译文
Mencius said, 'Wide territory and a numerous people are desired by the superior man, but what he delights in is not here. To stand in the centre of the kingdom, and tranquillize the people within the four seas - the superior man delights in this, but the highest enjoyment of his nature is not here. What belongs by his nature to the superior man cannot be increased by the largeness of his sphere of action, nor diminished by his dwelling in poverty and retirement - for this reason that it is determinately apportioned to him by Heaven. What belongs by his nature to the superior man are benevolence, righteousness, propriety, and knowledge. These are rooted in his heart; their growth and manifestation are a mild harmony appearing in the countenance, a rich fullness in the back, and the character imparted to the four limbs. Those limbs understand to arrange themselves, without being told.'
重点修订页
人工补强的解释层
核心问题
为什么孟子说“仁义礼智根于心”，而不是根于地位、疆土或成就？
直接回答
因为外在成就再大，也可能只是附加物；只有仁义礼智在心里扎根，一个人的大行或穷居才不会把他变成另一个人。真正决定人格的是根，而不是后来挂上的东西。
第一性原理
人的本性若有根，它必须在得失变化前后都还能成立；否则那就只是境遇，不是本性。
为什么重要
这章适合承接“仁义礼智根于心”“Mencius roots in the heart”“君子所性”这类搜索，是性善、修身与气象外化之间的关键连接点。
延伸阅读
这章在做什么
这章是《尽心上》第 21 / 46 章，最直接的进入线索是“广土众民，君子欲之，所乐不存焉”。放回全卷，它讨论的是尽心、诚与保存本心，并可与仁政、浩然之气互相印证。
更宽的搜索入口
如果你带着更宽的问题进入这一章，先从正确的 hub 页进入
全卷语境
《尽心上》重点是尽心、诚与如何保存已经给定的人心能力。
引用提示
不要把“见于面、盎于背”读成表演人格。孟子说的是：当根扎得足够深，人的外在气象会自然溢出，而不是刻意包装出来。