Originally Posted by BatLobsterRises
Well, I would agree that if we had to put a motive on The Joker, it would be his philosophy. I just don't like to think of it that way. That's like saying Batman's motive to do what he does is to stop crime and defend Gotham because its citizens are basically good and deserve saving. Yes, it's technically kind of true but it misses the full scope of why he chooses to do it in the particular way that he does it. I feel there's something inherently "unknowable" about The Joker's evil and that's part of his lasting appeal as a character. All of the villains in this series have a philosophy. But we don't get to know a single thing about where The Joker came from like we do with Bane, Ra's and Talia. We know what his worldview is, but not what shaped it or how it came to be. Same with Crane. We know how he views fear and its power over the mind, but not what caused him to be like that. With The Joker we don't even know why he went with the clown motif. It just is...and that's awesome.
How the Joker came to be the way he is has nothing to do with the fact that he DOES want to do something specific. The Joker has a specific goal and agenda. He has beliefs and ideals, and he spells them out in great length in the movie.
People reference his line to Harvey about him not being a schemer and just doing things, and completely miss the point that Joker was conning Harvey to break his mind and corrupt him in this scene. He was trying to claim that just because he was locked up in Gordon's cell at the time of what happened to Rachel and Harvey that meant he wasn't to blame for it. He wanted Harvey to go and kill the others, "the schemers" like Gordon, his Cops, the mob. The ones trying to control their little worlds. And it works. Harvey tells Maroni Joker is just a mad dog, and he wants the ones who let Joker off the leash.
How he came into the frame of mind that Gotham's morals and codes are all "a bad joke" and must be torn down is the mystery element of the character. You're right, it's awesome. That was Nolan's intention. Joker was to be an absolute. But he has a motive and an agenda. We just don't know how he came to have these crazy ideals.
But just listening to his two possible back stories, it's not hard to imagine how he got such a warped view of the world.