Spoilers ahead for The Dark Knight.

The Dark Knight, and the bulk of Christopher Nolan’s filmography, is about lies. It’s about the lies we tell ourselves in order to live and to interact with other people. For Nolan, he sees deception not as an inherently malevolent destructive force, but as a tool. After all, Nolan’s profession as a storyteller could be uncharitably framed as “professional liar.” He tells you things that haven’t happened in order to illuminate a larger truth, and Nolan’s films happen to be concerned with the nature of truth. Nowhere is that clearer than in The Dark Knight. While we could examine how the film changed the superhero genre or what it meant to the Batman franchise, for our purposes, I want to focus on how the film exists in the fascinating conflict between truth and lies, and how Nolan applies it beyond individuals and into a societal framework.

Since The Dark Knight is one of the highest grossing and most popular movies of all-time, I’m going to assume you’re familiar with the plot of Joker (Heath Ledger) coming to Gotham to “help” the mob kill Batman (Christian Bale), who has been bad for their business. Meanwhile, Batman has teamed up with Lieutenant Gordon (Gary Oldman) and Gotham’s “White Knight” District Attorney Harvey Dent (Aaron Eckhart) to take down organized crime in Gotham. It’s a basic crime-thriller set-up, but Nolan’s larger focus is on the lies that everyone is telling both to themselves and to each other. The Joker works on deception, tricking to the mob into thinking that he has any intention of killing Batman, while everyone else is working on delusion. The reason The Joker is so successful is that he doesn’t want anything beyond chaos. He has no identity to construct or higher aspiration than destruction. And because of this, he’s (in a deeply twisted fashion) the most honest character in the movie.

It’s not that The Joker doesn’t lie. He lies all the time to get what he wants. The opening sequence shows how he uses lies to manipulate people by allowing his crew to believe that they’ll get a bigger share by killing their partners. He lies to the mob to make them believe he’s their errand boy and not someone who’s robbing them. It would be tempting to believe that we can’t believe anything Joker says. After all, he’s a terrorist and a madman who, as Alfred (Michael Caine) so succinctly puts it, “Just wants to watch the world burn.” But the truth of the Joker is that he’s the biggest schemer of them all. He may have no greater goal in mind than the scheme, but he wants to show that order itself is a lie. “You see, their morals, their code, it's a bad joke. Dropped at the first sign of trouble,” Joker tells Batman. “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.” And in the end, he’s proven right.

The test of this belief would seem to be the boat experiment. Joker has a boat full of innocent civilians and another comprised of hardened criminals, and they each have a detonator to the other’s boat. If they don’t detonate to blow up the other ship, Joker will blow up both ships (it’s basically a writ large of the “tryouts” Joker holds earlier in the film). The civilians come a lot closer to blowing up the criminals than the other way around, but the experiment “fails.” People aren’t willing to kill to ensure their own survival, so not everyone is as “twisted” as Joker. But the ship experiment isn’t Joker’s endgame. The ship experiment is merely prelude to Joker’s plan with Harvey, which comes back around to how all of The Dark Knight is built on the lies we tell ourselves.

The notion that Gotham needs a White Knight at all is already a lie. Batman knows he can never be the symbol Gotham needs. He’s a vigilante working in the shadows. He’s a comforting, extrajudicial force that Gotham allows to operate. “They need you right now, but when they don’t, they’ll cast you out, like a leper!” The Joker correctly predicts. Batman’s hope, and the hope for the people of Gotham (represented by Gordon, the everyman) rests with Harvey. But in a movie built on foreshadowing words, Harvey writes his own epitaph when he says, “You either die a hero or you live long enough to see yourself become the villain.” However, Harvey’s villainous turn isn’t simply becoming Two-Face, but rather how he abdicates all responsibility in order to turn the world over to chance.

Harvey’s “truth” becomes not about restoring order, but by taking it away from people completely. He’s twisted by Joker. A man who “made his own luck” is now unable to make anything after the tragedy of losing Rachel (Maggie Gyllenhaal), so he turns everything over to his coin. Harvey gives up being part of the world and being an active player in it, and while the film’s larger focus is that positioning Harvey as Gotham’s savior was a mistake, Harvey’s villainy comes from discarding truth, lies, and everything else because he can’t live in a world that’s not ordered by unbiased chance. He’s still lying to himself, but it’s the only way he knows how to live.

And that doesn’t make him so different than Bruce. It’s a sly move for Nolan to take his hero and make him emblematic of the truth/lies dichotomy. We typically expect our heroes to be crusaders for good values. We accept that the truth is good (it’s something we’re told as children to always tell the truth), and therefore Batman should be on the side of truth. Except his entire existence is a lie. He’s actually billionaire Bruce Wayne, and he operates outside of the law. Batman is a benevolent lie to pacify Gotham. He’s there to clean up the streets and then from a public-facing perspective, Harvey Dent can take over and be the White Knight that Gotham needs. The cherry on top for Bruce is that once the work is done, he and Rachel can be together. For a man whose business is deception, Bruce fails to realize all the ways he lies to himself.

Nolan constantly returns to his fascination with lies and how they can be both benevolent and malevolent. They’re a primal force that can delight and destroy. In Memento, we’ve seen that Leonard Shelby, a man with no short-term memory, has built his existence on lies so he can keep moving forward. In Insomnia, Will Dormer built his reputation on a lie and tries to stay ahead of his lies because he believes the end justifies the means until the truth finally catches up with him. In The Prestige, Angier and Borden are both magicians—professional liars—but the lies Angier tells himself creates a cycle of endless death whereas Borden’s lie allows for his liberation and reunification with his daughter. Lies are tools, and in The Dark Knight, they allow for self-deception not just on a personal level, but a societal level.

What makes Joker so fearsome is that he threatens to expose a truth about human nature that could collapse society. If you break people’s spirit and they can’t handle that the best of us is actually a monster, then you deprive people of the lie they need the most—hope. Batman and Gordon decide that in order for society to function, it must be built on a benevolent lie. “Sometimes the truth isn’t good enough,” Batman says. “Sometimes people deserve more.” Just as storytelling uses lies to impose narrative order—the world makes sense if I align these fictions correctly—so too do Batman and Gordon conspire to tell Gotham a comforting lie. Batman takes responsibility for the murders committed by Harvey, and Harvey gets to “die a hero.” Maybe Batman and Gordon aren’t giving the people of Gotham enough credit, but their journey has led them to believe that society isn’t held together by the truth, but by benevolent lies. Even Bruce holds himself together with the lie that Rachel was going to wait for him and not stay with Harvey. The melancholy truth at the heart of The Dark Knight is that we need lies to hold our individual and collective psyches together. Because sometimes the truth isn’t good enough.

Tomorrow: Inception