The only thing I use my body for is to carry my brain around.

The stomach is the only part of man which can be fully satisfied. The yearning of man's brain for new knowledge and experience and for more pleasant and comfortable surroundings never can be completely met. It is an appetite which cannot be appeased.

Restlessness is discontent and discontent is the first necessity of progress. Show me a thoroughly satisfied man and I will show you a failure.

Nature made us - nature did it all - not the gods of the religions.

Negative results are just what I want. They’re just as valuable to me as positive results. I can never find the thing that does the job best until I find the ones that don’t.

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.

I never failed. It just didn't work 10,000 times.