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

I never did anything by accident, nor did any of my inventions come by accident; they came by work.

Being busy does not always mean real work. The object of all work is production or accomplishment and to either of these ends there must be forethought, system, planning, intelligence, and honest purpose, as well as perspiration. Seeming to do is not doing.

I never did a day's work in my life. It was all fun.

Maturity is often more absurd than youth and very frequently is most unjust to youth.

What you are will show in what you do.

There is no substitute for hard work.

Just because something doesn't do what you planned it to do doesn't mean it's useless.

It is very beautiful over there.

Genius is 1% inspiration, and 99% perspiration.