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

The opposite of every great idea is another great idea.

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

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

Truth and clarity are complementary.

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

In physics we deal with states of affairs much simpler than those of psychology and yet we again and again learn that our task is not to investigate the essence of things-we do not at all know what this would mean&mash;but to develop those concepts that allow us to speak with each other about the events of nature in a fruitful manner.