An expert is a person who has made all the mistakes that can be made in a very narrow field.

The very nature of the quantum theory ... forces us to regard the space-time coordination and the claim of causality, the union of which characterizes the classical theories, as complementary but exclusive features of the description, symbolizing the idealization of observation and description, respectively.

Those who are not shocked when they first come across quantum theory cannot possibly have understood it.

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.