"Comedy is subjective, Murray. Isn't that what they say? All of you, the system that knows so much, you decide what's right or wrong. The same way that you decide what's funny or not."
In that quote lies our current fate, the relativistic dark night that has descended on our world since Nietzsche issued his warning about the encroaching nihilism. The system that knows and controls so much decides human truth and what is good and evil, always of course, deciding in its own favor, even to suggest that all is woe and all hope is gone while heading to the bank with its ill-begotten lucre.
This is the void that frames the film, the nihilistic void that so many wish to avoid. To question. To ask themselves where their culpability lies and what is it, beyond creature comforts and social acceptance, that they truly believe. To understand why jokers like Arthur pop up everywhere.
But people like Arthur get pushed and pushed to the brink, and they look over and see nothing, not even their own reflections in the water, and conclude that that their only hope is to strike back at the people who personify the systemic violence that reduces them to non-entities.
After being tormented by three Wall St. types on the subway while in his clown costume, he finally strikes back and kills them after they sing "Send in the Clowns" to harass him. This gains him anonymous notoriety which he starts to relish. "For my whole life I didn't know I even really existed," he says, "but I do. People are starting to notice."
Of course they aren't noticing Arthur, but the masked clown whom they now fear. For Joker is the ultimate ironist, a man without a face, the faceless modern, just as all those who hide behind their wealth and public performances are masked actors in a bad play, one they try to control but which sometimes gets out of hand.
For those who say the film encourages violence, I say no; it holds a mirror up to the violence that undergirds the system of economic and political exploitation that already exists. Of course this too is ironic for a Hollywood movie. Like the films that it echoes Taxi Driver, The King of Comedy, Network Joker, like all good works of art, is open to polysemous interpretations. It encourages introspection and extrospection. It asks viewers to question themselves and their part in the social charade that passes for a just and equitable society. It asks viewers to contemplate Dr. Martin Luther King's statement that is as true now as when he uttered it: "The greatest purveyor of violence in the world: My own government. I cannot be silent."
The joker's joke is no joke at all. It is deadly serious.
When Arthur Fleck says, "I used to think my life was a tragedy, but now I realize it's a comedy," and unleashes his murderous violent rage with a Joker's smile, he was turning into those he condemned as his oppressors. Their nihilism became his own; their violence his.
The film asks us to contemplate such a marriage of seeming opposites, its dialectic, and not turn away from the faces in the mirror.
"Have you ever noticed that it is the most civilized gentlemen who have been the subtlest slaughterers, to whom the Attilas and the Stenka Razins could not hold a candle, and if they are not so conspicuous as the Attilas and Stenka Razins it is simply because they are so often met with, are so ordinary and have become so familiar to us."
Thus says Dostoevsky's Underground man.
But where are the rats?
Quick, send in the rats.
Don't bother, they're here.
They have taken complete ownership of Gotham City.