I see in Nature a magnificent structure... that must fill a thinking person with a feeling of humility.

Non-cooperation in military matters should be an essential moral principle for all true scientists.

When a man points a finger at someone else, he should remember that three of his fingers are pointing at himself. Do not worry about your difficulties in mathematics; I can assure you that mine are still greater.

The majority of the stupid is invincible and guaranteed for all time. The terror of their tyranny, however, is alleviated by their lack of consistency.

Isn't it strange that I who have written only unpopular books should be such a popular fellow?

Reason is intuition's servant.

When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity.