How wonderful that we have met with a paradox. Now we have some hope of making progress.

It is wrong to think that the task of physics is to find out how Nature is. Physics concerns what we say about Nature.

The best weapon of a dictatorship is secrecy, but the best weapon of a democracy should be the weapon of openness.

Prediction is very difficult, especially if it's about the future.

While the finish given to our picture of the world by the theory of relativity has already been absorbed into the general scientific consciousness, this has scarcely occurred to the same extent with those aspects of the general problem of knowledge which have been elucidated by the quantum theory.

Prediction is very difficult, especially if it's about the future.

The opposite of a fact is falsehood, but the opposite of one profound truth may very well be another profound truth.

Every great and deep difficulty bears in itself its own solution. It forces us to change our thinking in order to find it.

Your theory is crazy, but it's not crazy enough to be true.

When it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images.