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

I know this world is ruled by infinite intelligence. Everything that surrounds us- everything that exists - proves that there are infinite laws behind it. There can be no denying this fact. It is mathematical in its precision.

The only time I really become discouraged is when I think of all the things I would like to do and the little time I have in which to do them.

Show me a completely contented person and I'll show you a failure.

I have never seen the slightest scientific proof of the religious ideas of heaven and hell, of future life for individuals, or of a personal God.

Through all the years of experimenting and research, I never once made a discovery. I start where the last man left off... All my work was deductive, and the results I achieved were those of invention pure and simple.

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.