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

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 and establishing mental connections.

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.

Never express yourself more clearly than you are able to think.

What is that we human beings ultimately depend on? We depend on our words. We are suspended in language. Our task is to communicate experience and ideas to others.

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

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