Reply #70: The Joker's speech to Harvey Dent in The Dark Knight:

[Initech]

The Joker: Do I really look like a guy with a plan? You know what I am? I'm a dog chasing cars. I wouldn't know what to do with one if I caught it. You know, I just... do things. The mob has plans, the cops have plans, Gordon's got plans. You know, they're schemers. Schemers trying to control their little worlds. I'm not a schemer. I try to show the schemers how pathetic their attempts to control things really are. So, when I say... Ah, come here.
When I say that you and your girlfriend was nothing personal, you know that I'm telling the truth. It's the schemers that put you where you are. You were a schemer, you had plans, and look where that got you. I just did what I do best. I took your little plan and I turned it on itself. Look what I did to this city with a few drums of gas and a couple of bullets. Hmmm? You know... You know what I've noticed? Nobody panics when things go "according to plan." Even if the plan is horrifying! If, tomorrow, I tell the press that, like, a gang banger will get shot, or a truckload of soldiers will be blown up, nobody panics, because it's all "part of the plan." But when I say that one little old mayor will die, well then everyone loses their minds! Introduce a little anarchy. Upset the established order, and everything becomes chaos. I'm an agent of chaos. Oh, and you know the thing about chaos? It's fair!