国英问：「曾子『三省』虽切，恐是未闻『一贯』时工夫？」
先生曰：「『一贯』是夫子见曾子未得用功之要，故告之。学者果能忠、恕上用功，岂不是『一贯』？『一』如树之根本，『贯』如树之枝叶；未种根，何枝叶之可得？体、用一源，体未立，用安从生？谓『曾子于其用处，盖已随事精察而力行之，但未知其体之一。』，此恐未尽。」
国英问：「曾子『三省』虽然恳切，恐怕是未闻『一贯』之前的功夫？」
先生说：「『一贯』是孔子见曾子还没掌握用功的要领才告诉他的。学者果真能在忠恕上用功，岂不就是『一贯』？『一』如同树的根，『贯』如同树的枝叶；不先种根，哪来的枝叶？体用一源，体未立，用从哪里生出？说『曾子在其用处已能随事精察而力行，只是还不知体的统一』，这话恐怕未尽。」
Guoying asked: 'Zengzi's thrice-daily self-examination, earnest as it is, was surely before hearing of the one thread?'
The Master said: 'Confucius spoke of the one thread only because he saw Zengzi had not yet grasped the essential of effort. If learners truly work at loyalty and reciprocity, is that not the one thread? The one is the tree's root, the thread its branches and leaves: no root planted, whence the leaves? Substance and function are one source; before substance stands, whence function springs? To say Zengzi had already examined each affair finely and practiced it, only not yet knowing the unity of substance — that hardly does him justice.'