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

A man is never more serious than when he praise himself.

We have to believe that everything has a cause, as the spider spins its web in order to catch flies. But it does this before it knows there are such things as flies.

Perseverance can lend the appearance of dignity and grandeur to many actions, just as silence in company affords wisdom and apparent intelligence to a stupid person.

Do not say hypothesis, and even less theory: say way of thinking.

Pain warns us not to exert our limbs to the point of breaking them. How much knowledge would we not need to recognize this by the exercise of mere reason.

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.