How can your child know men, when he can neither judge of their judgments nor unravel their mistakes? It is a misfortune to know what they think, without knowing whether their thoughts are true or false.
 Jean-Jacques Rousseau, Emile, or On Education (1762). copy citation

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Author Jean-Jacques Rousseau
Source Emile, or On Education
Topic misfortune judgment
Date 1762
Language English
Reference
Note Translated by Barbara Foxley
Weblink http://www.gutenberg.org/cache/epub/5427/pg5427-images.html

Context

“This is the final study of the philosopher, and you expect to make it the first lesson of the child! Before teaching him our sentiments, first teach him to judge of their worth. Do you perceive folly when you mistake it for wisdom? To be wise we must discern between good and evil. How can your child know men, when he can neither judge of their judgments nor unravel their mistakes? It is a misfortune to know what they think, without knowing whether their thoughts are true or false. First teach him things as they really are, afterwards you will teach him how they appear to us. He will then be able to make a comparison between popular ideas and truth, and be able to rise above the vulgar crowd;” source