Most of my ideas belonged to other people who never bothered to develop them.

When you have exhausted all possibilities, remember this - you haven't.

My success is due more to my ability to work continuously on one thing without stopping than to any other single quality.

The entity that gives life and motion to the human body is finer still and lies infinitely beyond the reach of our finest scientific instruments. When this entity deserts the body, the body is like a ship without a rudder - deserted, motionless, dead.

This problem, once solved, will be simple.

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

The first requisite for success is to develop the ability to focus and apply your mental and physical energies to the problem at hand - without growing weary. Because such thinking is often difficult, there seems to be no limit to which some people will go to avoid the effort and labor that is associated with it.