The biggest failure of man is that he gives up before he realizes how close he was to success.

The endeavor to change universal power by selfish supplication I do not believe in.

The doctor of the future will no longer treat the human frame with drugs, but rather will cure and prevent disease with nutrition.

I am not overly impressed by the great names and reputations of those who might be trying to beat me to an invention. It's their 'ideas' that appeal to me. I am quite correctly described as 'more of a sponge than an inventor

Nothing that's good works by itself, you've got to make the damn thing work.

I have not failed 10,000 times. I have succeeded in proving that those 10,000 ways will not work.

I consider Paine our greatest political thinker. As we have not advanced, and perhaps never shall advance, beyond the Declaration and Constitution, so Paine has had no successors who extended his principles.