Conscience. Live by it.
From The Ox Bow Incident
The lynched man's last letter...
"...A man just naturally can't take the law into his own hands and hang people without hurtin' everybody in the world, 'cause then he's just not breakin' one law, but all laws. Law is a lot more than words you put in a book, or judges or lawyers or sheriffs you hire to carry it out. It's everything people ever have found out about justice and what's right and wrong. It's the very conscience of humanity. There can't be any such thing as civilization unless people have a conscience, because if people touch God anywhere, where is it except through their conscience? And what is anybody's conscience except a little piece of the conscience of all men that ever lived? I guess that's all I've got to say except - kiss the babies for me and God bless you..."