Failure is really a matter of conceit. People don't work hard because, in their conceit, they imagine they'll succeed without ever making an effort. Most people believe that they'll wake up some day and find themselves rich. Actually, they've got it half right, because eventually they do wake up.

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.

Our greatest weakness lies in giving up.

When there's no experimenting there's no progress. Stop experimenting and you go backward. If anything goes wrong, experiment until you get to the very bottom of the trouble.

I will not say I failed 1000 times, I will say that I discovered there are 1000 ways that can cause failure

To invent, you need a good imagination and a pile of junk.

Most of my ideas belonged to other people who never bothered to develop them.