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

Never be discouraged, because every wrong turn attempt, when left behind you, is another step forward taking you closer to your goals.

No Such Thing as Bad Results

It is astonishing what an effort it seems to be for many people to put their brains definitely and systematically to work.

My mind is incapable of conceiving such a thing as a soul. I may be in error, and man may have a soul; but I simply do not believe it.

I never once failed at making a light bulb. I just found out 99 ways not to make one.

It is the best book ever written on the subject. There is nothing like it!