"I choose my friends for their good looks, my acquaintances for their good characters, and my enemies for their good intellects. A man cannot be too careful in the choice of his enemies."

"A man who does not think for himself does not think at all."

"All women become like their mothers. That is their tragedy. No man does. That's his."

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

"A good friend will always stab you in the front."