Hour of the Gun (1967)

Wyatt Earp (Tombstone city marshal: I don't care about the rules anymore. I'm not that much of a hypocrite.
Dr. John 'Doc' Holliday: The whole thing is hypocrisy. The rules they tack on today that unless you're wearing that badge or a soldier's uniform, you can't kill. But they're the only rules there are. They are more important to you than you think. Play it that way, Wyatt, or you'll destroy yourself.