From his neck down a man is worth a couple of dollars a day, from his neck up he is worth anything that his brain can produce.

The trouble with most people is that they quit before they start.

Just because something doesn't do what you planned it to do doesn't mean it's useless.

I would rather have one man with enthusiasm working with me than ten who are complacent.

It is very beautiful over there. (last words)

I have a peculiar theory about radium, and I believe it is the correct one. I believe that there is some mysterious ray pervading the universe that is fluorescing to it. In other words, that all its energy is not self-constructed but that there is a mysterious something in the atmosphere that scientists have not found that is drawing out those infinitesimal atoms and distributing them forcefully and indestructibly.

Books will soon be obsolete in the schools... Our school system will be completely changed in the next ten years.