TDK
I've heard it said that a comic book super-hero movie can't relate exterior truths, that it's silly and self-indulgent for one to try. To me, that sentiment says more about the person doing the speaking than it does the type of movie being described. Comic books grew up more than twenty years ago, after all. But more importantly than that, super-hero comics, by their nature, have always been able and willing to tell the great and simplistic truths. Good, evil, violence, peace, crime, justice - all shown clearly delineated and separated, in three or four colors, in virtually every superhero comic ever made. Who else, what style and story, is better suited to show that line between order and chaos, when that is the essence of the super-hero ethos?
Chris Nolan and the creators of Batman Begins and The Dark Knight understand that more than any other movie makers have. Both movies were about good and evil, yes; but more than that, they were about choice, and fear, and mind, and whether those lines are really drawn that deep. As fun as it to watch the good guys kick some ass, it's far more interesting to see why the bad guys need their asses kicked in the first place. From what they do to why they do it to what makes them the way they are: we go to these movies not for the super-heroes, but for the super-villains. And that's always what Batman has been about.
Batman has always been more interesting to me than the other super-heroes, for the same reason he apparently is to others - he's not, actually, a super-hero. He's just a man, a man of means and will, who decides to take matters into his own hands. In that sense he's little different than the enemies he fights; none of his multitude of fascinating villains have any powers beyond their own imaginations and control over others. This lack of the supernatural serves to emphasize that what makes these characters, both Batman and those on the other side of the line he draws, is what could make anyone. Anyone could be damaged enough to hurt others and seek pain; anyone could be damaged and seek to prevent that damage from spreading. The Batman franchise, more than almost any other story in mainstream fiction, is one rooted in the heart of psychosis, and the origin of chaos. The Nolan Batman, and the Ledger Joker, contain the truth of that theme and make it more.
The Dark Knight is more than a super-hero movie, and better, because it's not about good and evil. Not really. Most movies that abolish that distinction imply that there is no true evil, only pain and misunderstanding; The Dark Knight says that there is no true good, only the fear of and choice to avoid evil. It says that everyone has darkness in their heart, and that the only distinction between the good guys and the bad guys is the way they act upon it. This Joker is inhuman, unnatural, evil, profoundly disturbing. Yet he is still only the embodiment of what anyone could become. True jokers exist, with less style and sense of the dramatic, in the form of the serial killers and criminals with whom we are all familiar; this Joker is so terrifying partly because he is so real. He acts as a mirror, showing the extreme of what humanity is capable of becoming. As his actions force the laughter of shock and horror from the audience, and his logic of destruction begins to make a twisted sort of sense, he forces those watching to examine themselves in a way that only true art can.
Yet, there is no story - no true one, anyway - to tell why this Joker is the way he is; only his actions are shown. He is a symbol, to the audience, in a way that Bruce Wayne's Batman can never be. Indeed, the only two to have their stories shown are the Batman himself and Two-Face, Harvey Dent. They act as, in an obvious metaphor, two sides of the same coin. Together, they represent the heart of the movie: that the relationship between good and evil is nothing but a matter of choice. When Bruce Wayne's mother and father are taken from him, he chooses to try to prevent tragedy and pain from striking others; when Harvey Dent's love and future are taken from him, he chooses to spread them. Gotham's white knight, the city's hope, succumbs to the darkness in his heart, and seeks revenge on those he deems responsible for his pain - those that saved his life in the first place. That anyone, even the best of us, could become what Harvey Dent became is a truth that few stories in fiction tell. Yet it is self-evident; some part of each of us has always known it. We distrust the good, for we know the Joker's philosophy is at least partly true: order and civilization are only the masks we throw over the chaos that is humanity.
There is hope in the movie's story, though, that humanity is not a self-devouring snake, that the choice for good is as easy to make as the choice for evil. The Joker's simplest, most fiendish plan - that either those on each of the two ferries can choose to live at the expense of the other, or both ferries will explode if neither of them choose - is ruined by his underestimation of people as a whole. None, of all of them, choose to doom the other ferry's passengers and save themselves; therefore, the Joker's lie is revealed, and none of them die. A truth is told here, too, albeit one whose veracity the movie inclines us to distrust. Everyone holds darkness and chaos in their heart, yes: but more choose to control it than not. Perhaps people are fundamentally good and evil is an aberration, perhaps the opposite is true; but society continues its merry trip in one direction or the other, and the criminally insane that proliferate in Gotham are relatively rare in our world. The Dark Knight's world is an exaggeration of our own, an instrument that takes our world's darkest hearts and magnifies them to be clearly seen. Its appeal lies in its relation to reality. Its excellence lies in its purity of execution. Go see it. It's worth it.