“The right to swing my fist ends where the other man’s nose begins.”
Oliver Wendell Holmes

I have a mind to join a club and beat you over the head with it."
Groucho Marx

"I like a man who grins when he fights."
Sir Winston Churchill

"Nothing good ever comes of violence."
Martin Luther

"The man who strikes first admits that his ideas have given out."
Chinese Proverb

"There will one day spring from the brain of science a machine or force so fearful in its potentialities, so absolutely terrifying, that even man, the fighter, who will dare torture and death in order to inflict torture and death, will be appalled, and so abandon war forever."
Thomas Alva Edison

"Violence isn't always evil. What's evil is the infatuation with violence."
Jim Morrison (lead singer of The Doors) 

“Many a man’s tongue broke his nose.”
Seamus MacManus

Violence is the last refuge of the incompetent.
Isaac Asimov

Intolerance is itself a form of violence and an obstacle to the growth of a true democratic spirit.
Mahatma Gandhi

Education is the vaccine for violence.
Edward James Olmos

Violence, even well intentioned, always rebounds upon oneself.
Lao Tzu