The value of an idea lies in the using of it.

To have a great idea, have a lot of them.

Our greatest weakness lies in giving up. The most certain way to succeed is always to try just one more time.

One might think that the money value of an invention constitutes its reward to the man who loves his work. But... I continue to find my greatest pleasure, and so my reward, in the work that precedes what the world calls success.

Nearly every man who develops an idea works it up to the point where it looks impossible, and then he gets discouraged. That's not the place to become discouraged.

Our greatest weakness lies in giving up.