Confucius said to a disciple,"Shall I teach you what is understanding? To know what it is that you know, and to know what it is that you do not know,——that is understanding."
中文:子曰:“由!诲汝知之乎?知之为知之,不知为不知,是知也。”
注释:孔子对一个学生说:“让我告诉你什么是聪明吧?要知道什么东西是你所知道的,也要知道什么东西是你所不知道的——这就是聪明。”