A difference of opinion is what makes horse racing and missionaries.
Will Rogers (1879-1935) 

A man may die, nations may rise and fall, but an idea lives on.
John F. Kennedy (1917-1963) 

A new idea is delicate. It can be killed by a sneer or a yawn; it can be stabbed to death by a joke or worried to death by a frown on the right person's brow.
Charles Brower 

Anyone who has never made a mistake has never tried anything new.
Albert Einstein (1879-1955) 

Creativity is allowing oneself to make mistakes. Art is knowing which ones to keep.
Scott Adams  - The Dilbert Principle

Creativity often consists of merely turning up what is already there. Did you know that right and left shoes were thought up only a little more than a century ago?
Bernice Fitz-Gibbon 

Discovery consists in seeing what everyone else has seen and thinking what no one else has thought.
Albert Szent-Gyorgi  , 1937 Nobel Prize in Physiology and Medicine

Do not fear to be eccentric in opinion, for every opinion now accepted was once eccentric.
Bertrand Russell (1872-1970) 

Don't worry about people stealing your ideas. If your ideas are any good, you'll have to ram them down people's throats.
Howard Aiken 

Even if you're on the right track, you'll get run over if you just sit there.
Will Rogers (1879-1935)