One of the greatest creations of the human mind is the art of reviewing books without having read them.

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

The fly that doesn't want to be swatted is most secure when it lights on the fly-swatter.

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.

Non cogitant, ergo non sunt.

Everyone should study at least enough philosophy and belles-lettres to make his sexual experience more delectable.

The most heated defenders of a science, who cannot endure the slightest sneer at it, are commonly those who have not made very much progress in it and are secretly aware of this defect.