The old saying of the two kinds of truth. To the one kind belongs statements so simple and clear that the opposite assertion obviously could not be defended. The other kind, the so-called “deep truths,” are statements in which the opposite also contains deep truth.

No, no, you're not thinking, you're just being logical.

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

Prediction is very difficult, especially about the future.

Anyone who is not shocked by quantum theory has not understood it.

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

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

Anybody who is not shocked by this subject has failed to understand it.

Never express yourself more clearly than you think.