“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.”

“[On famous Nobel Laureate Niels Bohr][Niels] Bohr's sort of humor, use of parables and stories, tolerance, dependence on family, feelings of indebtedness, obligation, and guilt, and his sense of responsibility for science, community, and, ultimately, humankind in general, are common traits of the Jewish intellectual. So too is a well-fortified atheism. Bohr ended with no religious belief and a dislike of all religions that claimed to base their teachings on revelations.”

“I have been connected with the Niels Bohr Institute since the completion of my university studies, first as a research fellow and, from 1956, as a professor of physics at the University of Copenhagen. After the death of my father in 1962, I followed him as director of the Institute until 1970.”

“Prediction is very difficult, especially if it's about the future.”

“When it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images.”

“Technology has advanced more in the last thirty years than in the previous two thousand. The exponential increase in advancement will only continue.”

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

“The opposite of a fact is falsehood, but the opposite of one profound truth may very well be another profound truth.”

“While the finish given to our picture of the world by the theory of relativity has already been absorbed into the general scientific consciousness, this has scarcely occurred to the same extent with those aspects of the general problem of knowledge which have been elucidated by the quantum theory.”

“Einstein, stop telling God what to do!”

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