"The difference between the poet and the mathematician is that the poet tries to get his head into the heavens while the mathematician tries to get the heavens into his head."
"There is a great deal of difference between an eager man who wants to read a book and a tired man who wants a book to read."
"A dead thing goes with the stream, but only a living thing can go against it."
"I am not absentminded. It is the presence of mind that makes me unaware of everything else."
"Great truths can only be forgotten and can never be falsified."
"If a thing is worth doing, it is worth doing badly."