“Those who know do not speak; those who speak do not know”: did Laozi say it?
Genuine: chapter 56
Yes: “Those who know do not speak; those who speak do not know” is the first line of chapter 56 of the Dao De Jing, 知者不言，言者不知, translated word for word.
Those who know do not speak; those who speak do not know.
What the Dao De Jing says
-
知者不言，言者不知。
Those who know do not speak; those who speak do not know.
What the Chinese says
Eight characters in two halves that mirror each other. 知者不言: “knowing one, not speaking”. 言者不知: “speaking one, not knowing”. The saying in English follows the Chinese closely; nothing is added.
How translations differ
The Chinese does not say what is known. James Legge (1891) filled it in: “He who knows (the Tao) does not (care to) speak (about it)”, with his additions in brackets. Most modern versions leave it open, as we do. The chapter goes on to “close the openings, shut the doors”, which reads the line as a lesson in restraint rather than a rule against talking.
An old objection
The Tang poet Bai Juyi (白居易) turned the line against its author in a short poem, 读老子 (“Reading Laozi”): if Laozi was one who knew, why did he write five thousand characters?