知之为知之
Knowing what you do not know
知之为知之，不知为不知，是知也。
To know what you know, and to know what you do not know — that is knowledge.
论语 · 为政篇
· our translation
Confucius defines knowing as being able to tell what you know from what you don't. A name takes this as the firm ground of the word.
孔子给「知」下的定义：不是知道得多，是分得清自己知道什么、不知道什么。名字取「知」，最硬的一层就在这。
知者不惑
Not confused
知者不惑，仁者不忧，勇者不惧。
The wise are not perplexed, the humane are not anxious, the brave are not afraid.
论语 · 子罕篇
· our translation
The three classical virtues, each answering one difficulty: wisdom answers confusion.
《论语》里三达德并称的一句：智、仁、勇各解一种困境——「知」解的是迷惑。
知者乐水
Why the wise like water
知者乐水，仁者乐山。
The wise take pleasure in water; the humane take pleasure in mountains.
论语 · 雍也篇
· our translation
Water moves, changes, yields downward and keeps its nature. Confucius gives water to the wise and mountains to the humane.
水是动的、变的、往低处走却不失其性——孔子把「知」比作水，山留给仁。这一层让「知」不只是聪明。
知者明辨见知知远知微知白知行
In a name
Not cleverness: the ability to tell things apart.
「知」在名字里不是「聪明」，是分得清。