"Without conflict, there is no action. Without action, there is no character. Action is Character. What a person does is what he is, not what he says."
"Character is the essential internal foundation of your screenplay. The cornerstone. It is the heart and soul and nervous system of your screenplay. Before you can put one word down on paper, you must know your character."
- from 'Screenplay, The Foundations of Screenwriting' by Syd Field