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

If anybody says he can think about quantum physics without getting giddy, that only shows he has not understood the first thing about them.

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.

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

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

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