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

It is, indeed, perhaps the greatest prospect of humanistic studies to contribute through an increasing knowledge of the history of cultural development to that gradual removal of prejudices which is the common aim of all science.

It is the hallmark of any deep truth that its negation is also a deep truth.

Some things are so serious, they can only be joked about.

You must come to Copenhagen to work with us. We like people who can actually perform thought experiments!

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

Anybody who is not shocked by this subject has failed to understand it. [of quantum mechanics]