"The only thing to do with good advice is to pass it on. It is never of any use to oneself."

"The advantage of the emotions is that they lead us astray, and the advantage of science is that it is not emotional."

"Conversation should be a duel and not a concert."

"We are all in the gutter, but some of us are looking at the stars."

"I am so clever that sometimes I don't understand a single word of what I am saying."