Your worth consists in what you are and not in what you have.

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

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.

I know of over 3,000 ways [that] a light bulb does not work.

I get my ideas from listening from within.

We have merely scratched the surface of the store of knowledge which will come to us. I believe that we are now, a-tremble on the verge of vast discoveries - discoveries so wondrously important they will upset the present trend of human thought and start it along completely new lines .

Inspiration can be found in a pile of junk. Sometimes, you can put it together with a good imagination and invent something.