Book 2: 《為政》 Wei Zheng (Governance)
《為政》 Passage 2.17
子曰：「由！誨女知之乎？知之為知之，不知為不知，是知也。」
Legge Translation (1861)
The Master said: "Yu, shall I teach you what knowledge is? When you know a thing, to hold that you know it; and when you do not know a thing, to acknowledge that you do not know it; — this is knowledge."