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

A deep truth is a truth so deep that not only is it true but it's exact opposite is also true.

Of course I don't believe in it [pointing to horseshoe on his office wall]. But I understand that it brings you luck whether you believe in it or not.

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

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

Accuracy and clarity of statement are mutually exclusive.

Predition is risky, especially of the future.