“What sort of philosophers are we, who know absolutely nothing of the origin and destiny of cats?”

“There is danger that we lose sight of what our friend is absolutely, while considering what she is to us alone.”

“To know that we know what we know, and that we do not know what we do not know, that is true knowledge.”

“Confucius said, "To know that we know what we know, and that we do not know what we do not know, that is true knowledge.”

“To a philosopher all news is gossip, and they who edit and read it are old women over their tea.”

“We hear and apprehend only what we already half know.”

“There are nowadays professors of philosophy, but not philosophers.”