he is a man of wisdom, but he is still a man. With the greatest penetration, the nicest discrimination, and the most profound knowledge of men, he sometimes suffers himself to be deceived, and never recovers his error. His temper is very singular and foreign to his general turn of mind. He seems to forget the people he sees every day, and thinks of them in a moment when they least expect it
 Jean-Jacques Rousseau, Confessions (1782). copy citation

add
Author Jean-Jacques Rousseau
Source Confessions
Topic wisdom suffering
Date 1782
Language English
Reference
Note Translated by Samuel William Orson
Weblink https://en.wikisource.org/wiki/Confessions_(Rousseau)

Context

“how deeply did they wound me when they deprived me of your friendship? But no, great man, you are and ever will be the same for me, who am still the same. You have been deceived, but you are not changed. My lord marechal is not without faults; he is a man of wisdom, but he is still a man. With the greatest penetration, the nicest discrimination, and the most profound knowledge of men, he sometimes suffers himself to be deceived, and never recovers his error. His temper is very singular and foreign to his general turn of mind. He seems to forget the people he sees every day, and thinks of them in a moment when they least expect it; his attention seems ill-timed; his presents are dictated by caprice and not by propriety. He gives or sends in an instant whatever comes into his head, be the value of it ever so small. A young Genevese, desirous of entering into the service of Prussia, made a personal application to him;” source