To start with invention is the mark of the fertile mind ... and leads later to the interpretation of experience; to start with the reproduction of experience is the infallible index of a barren invention.

The only sin passion can commit is to be joyless.

The only ethical principle which has made science possible is that the truth shall be told all the time. If we do not penalize false statements made in error, we open up the way for false statements by intention. And a false statement of fact, made deliberately, is the most serious crime a scientist can commit.

And what do all the great words come to in the end, but that? I love you - I am at rest with you - I have come home.

It is impossible for human nature to believe that money is not there. It seems so much more likely that the money is there and only needs bawling for.

I can't think why fancy religions should have such a ghastly effect on one's grammar. It's a kind of intellectual rot that sets in, I'm afraid.

Learning and literature have a way of outlasting the civilization that made them.