“We all know your idea is crazy. The question is whether it is crazy enough.”

If an idea does not appear bizarre, there is no hope for it.

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

Address to Albert Einstein: You are not thinking. You are merely being logical.

When it comes to atoms, language can be used only as in poetry.

There are some things so serious you have to laugh at them.

One must always do what one really cannot.

There is no hope for any speculation that does not look absurd at first glance.

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

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

If we couldn’t laugh at ourselves, that would be the end of everything.

An expert is a man who has made all the mistakes which can be made, in a narrow field.

Physics is the belief that a simple and consistent description of nature is possible.

Some subjects are so serious that one can only joke about them.

Sometimes the child in one behaves a certain way and the rest of oneself follows behind, slowly shaking its head.

It is, indeed, perhaps the greatest prospect of humanistic studies to contribute through an increasing knowledge of the history of cultural development to that gradual removal of prejudices which is the common aim of all science.

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.