Cherish the questions, for the answers keep changing.

One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike -- and yet it is the most precious thing we have.

If I were wrong, wouldn't one be enough?

The finest emotion of which we are capable is the mystic emotion.

Laws alone can not secure freedom of expression; in order that every man present his views without penalty there must be spirit of tolerance in the entire population.

We know nothing at all. All our knowledge is but the knowledge of schoolchildren. The real nature of things we shall never know.

Creativity is seeing what others see and thinking what no one else has ever thought.