"An expert is a person who has found out by his own painful experience all the mistakes that one can make in a very narrow field."

“Oh, what idiots we all have been. This is just as it must be.”

“I am absolutely prepared to talk about the spiritual life of an electronic computer: to state that it is reflecting or is in a bad mood... The question whether the machine really feels or ponders, or whether it merely looks as though it did, is of course absolutely meaningingless.”

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

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

“Every valuable human being must be a radical and a rebel, for what he must aim at is to make things better than they are.”

“It is not enough to be wrong, one must also be polite.”