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

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

A teacher sent the following note home with a six-year-old boy 'He is too stupid to learn.' That boy was Thomas A. Edison.

My main purpose in life is to make enough money to create ever more inventions…. The dove is my emblem…. I want to save and advance human life, not destroy it…. I am proud of the fact that I have never invented weapons to kill….

We shall have no better conditions in the future if we are satisfied with all those which we have at present.

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

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