Master Roshi's words of wisdom

"We do not learn martial arts to pick fights or to impress girls who will say "Oh beefcake, you're so strong, I want you." Heh. Muah. (does a kissing motion) Do you understand what I am saying? We must master the art of peace in addition to the art of war. We achieve victory by the art of war, victory is won through strategy, strategy is derived from the art of peace. However if somebody evil threatens you or any other good innocent people with unethical force it is your duty to defend!"
— Master Roshi explaining the ways of the Turtle School to Krillin and Goku in "Milk Delivery"