Anybody who has been seriously engaged in scientific work of any kind realizes that over the entrance to the gates of the temple of science are written the words: 'Ye must have faith.'

Every advance in knowledge brings us face to face with the mystery of our own being.

We have no right to assume that any physical laws exist, or if they have existed up until now, that they will continue to exist in a similar manner in the future.

A new truth always has to conend with many difficulties. If it were not so, it would have been discovered much sooner.

Scientific discovery and scientific knowledge have been achieved only by those who have gone in pursuit of it without any practical purpose whatsoever in view.

An important scientific innovation rarely makes its way by gradually winning over and converting its opponents: What does happen is that the opponents gradually die out.

No burden is so heavy for a man to bear as a succession of happy days.