Through the fortunate effect of my frankness, I had the rarest and surest opportunity to know a man well, which is to study him at leisure in his private life and living, so to speak, with himself. For he share himself without reservation and made me feel as much at home in his house as in mine. I had almost no other abode than his own.

Second Dialogue - Dialogues: Rousseau Judge of Jean-Jacques (published 1782)