Batman: Then why do you want to kill me?
The Joker: [giggling] I don't, I don't want to kill you! What would I do without you? Go back to ripping off mob dealers? No, no, NO! No. You... you... complete me.
Batman: You're garbage who kills for money.
The Joker: Don't talk like one of them. You're not! Even if you'd like to be. To them, you're just a freak, like me! They need you right now, but when they don't, they'll cast you out, like a leper! You see, their morals, their code, it's a bad joke. Dropped at the first sign of trouble. They're only as good as the world allows them to be. I'll show you. When the chips are down, these... these civilized people, they'll eat each other. See, I'm not a monster. I'm just ahead of the curve.