Everything we call real is made of things that cannot be regarded as real.

There are some things so serious you have to laugh at them.

An expert is a man who has made all the mistakes which can be made, in a narrow field.

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

If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet.

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