I have friends in overalls whose friendship I would not swap for the favor of the kings of the world.

I have not failed. I've just found 10,000 ways that won't work.

In 'Common Sense' Paine flared forth with a document so powerful that the Revolution became inevitable. Washington recognized the difference, and in his calm way said that matters never could be the same again.

Personally, I enjoy working about 18 hours a day. Besides the short catnaps I take each day, I average about four to five hours of sleep per night.

I never view mistakes as failures. They are simply opportunities to find out what doesn't work.

I was always afraid of things that worked the first time. Long experience proved that there were great drawbacks found generally before they could be got commercial; but here was something there was no doubt of.

Success depends on how many experiments you can fit into 24 hours