Niels Bohr

"The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth."

"Prediction is very difficult, especially about the future."

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

"There are trivial truths and there are great truths. The opposite of a trivial truth is plainly false. The opposite of a great truth is also true."

"The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth."

"Prediction is very difficult, especially about the future."

"Stop telling God what to do with his dice."

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

"You can recognize a small truth because its opposite is a falsehood. The opposite of a great truth is another truth."

"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."