A clever child brought up with a foolish one can itself become foolish. Man is so perfectible and corruptible he can become a fool through good sense.

The natural scientists of the previous age knew less than we do and believed they were very close to the goal: we have taken very great steps in its direction and now discover we are still very far away from it. With the most rational philosophers an increase in their knowledge is always attended by an increased conviction of their ignorance.

What is called an acute knowledge of human nature is mostly nothing but the observer's own weaknesses reflected back from others.

Many things about our bodies would not seem to us so filthy and obscene if we did not have the idea of nobility in our heads.

A vacuum of ideas affects people differently than a vacuum of air, otherwise readers of books would be constantly collapsing.

Great men too make mistakes, and many among them do it so often that one is almost tempted to call them little men.

What a blessing it would be if we could open and shut our ears...as easily as we open and shut our eyes.