On last night's Person of Interest, a caper-style episode about an art thief, Finch refers to a fictional New York bar called The Purloined Letter. And that single reference, to an Edgar Allan Poe story, revealed how this show is entangled in one of the great philosophical debates of the last fifty years.


Many critics consider Poe's famous story "The Purloined Letter" to be one of the first detective stories, and its influence looms large in the genre — inspiring everything from a Sherlock Holmes tale, to a recent storyline on Downton Abbey. To understand how it fits into Person of Interest, let's recap the salient parts of Poe's story.

The Queen has lost a letter that contains information she's trying to hide from her husband, the King. It was stolen by the scheming Minister, who noticed her distress upon seeing the letter. She hides it in plain sight on a table, because the King is unlikely to notice it. As the helpless Queen watches, the Minister distracts the King with conversation and casually puts his own letter down next to the Queen's, then grabs hers before leaving. So he's switched the letters, but the Queen can say nothing because she doesn't want the King to know. She does, however, call her trusted Police Inspector.


After months of searching everywhere for the letter, scouring the Minister's rooms and building, the Inspector is at wit's end. So he calls on Poe's famous poet/detective Dupin, and asks him to consider the case. Dupin points out that the Inspector has underestimated the Minister's cleverness, because the Minister is a poet and the Inspector thinks all poets are mad. But in fact, the Minister has done something quite crafty, which Dupin deduces after he "casually" drops by the Minister's rooms. Like the Queen, the Minister hid the letter in plain sight. He's refolded it, tattered it a bit, and changed the address on the outside to his own. And he's put it in a gaudy letter holder in the middle of the room.

In a series of shenanigans worthy of the Machine Gang on Person of Interest, Dupin manages to pilfer the Queen's letter when the Minister isn't looking — snatching it up, Dupin leaves behind a duplicate letter he's crafted, with a snarky message inside to the Minister. By the time the Minister realizes his valuable letter is a duplicate, it's too late and the Inspector has given the secret letter back to the Queen. Crucially, none of the characters ever read the Queen's letter, so we as readers never know what it was. We just know how it was hidden and purloined, repeatedly.

This crime story has been the focus of a longstanding debate among philosophers and critical theorists since the 1960s, when French psychoanalyst Jacques Lacan presented his famous Seminar on the Purloined Letter.*


Let's consider just one of Lacan's main observations about the story, which is immediately relevant to Person of Interest. Lacan breaks the story down into scenes where three people's actions are structured around the letter. In each scene, the three people's positions are determined by what they see (and what they don't):

The first [position] is a glance that sees nothing: the King and the police. The second, a glance which sees that the first sees nothing and deludes itself as to the secrecy of what it hides: the Queen, then the Minister. The third sees that the first two glances leave what should be hidden exposed to whoever would seize it: the Minister, and finally Dupin.


What's remarkable, from Lacan's perspective, is the way the letter creates these same three positions twice in one story, with different characters filling them. You'll notice that these structures all involve acts of surveillance (or failed surveillance). To vastly oversimplify, Lacan views this odd repetition as an example of how certain meaningful objects seem to blaze their own pathways through social structures, causing specific scenarios to repeat again and again in a cyclic manner. Through this repetition, he concludes, "the 'purloined letter' . . . always arrives at its destination."


The interesting part, for fans of Person of Interest and stories like it, is the way Lacan so succinctly sums up those three positions, which crop up all the time in a certain subgenre of detective stories that are focused on secrets and surveillance. Consider, for a moment, the positions mapped onto Person of Interest.

The "purloined letter" is the number of the week.

The "first position" is the police or other government agency seeking the number. In general, they see absolutely nothing, or aren't even interested in the number in the first place. (The number is, by definition, "irrelevant" to the government.)


The "second position" is the bad guy or good guy who is entangled with the number, often in a violent way. They know about the number, and are secretly scheming to do something to them, but don't realize that their secret schemes are easily seen.

The "third position" is the Machine Gang. Thanks to the Machine, the Gang can always see the number, and they can see how it's connected to the second position. Basically they can see the second position's blind spots. (Sometimes literally, like when the Machine tells Root where to shoot.) Their job, like Dupin's, isn't justice exactly — it's to get the number out of a harmful situation.


So now let's talk about how this structure specifically relates to last night's caper episode. Our number is Jiao Lin, a former Olympic gymnast turned international art thief, who is being pursued by a mostly-clueless INTERPOL guy (first position). Like the purloined letter, Lin hides in plain sight, masquerading as an event planner in museums in order to get close to the objects she's going to steal. But as Shaw quickly discovers, Lin isn't a free agent.


In fact, Lin is in thrall to a gang of black market kingpins in Prague (second position), who have kidnapped her daughter and forced her to use her gymnast/ninja skills to steal for them. We learn this when Lin meets her Prague Guy contact at a bar called The Purloined Letter. Which is more than a hint and a half that we're in Poe territory — but also Lacan territory, too. These Prague guys think nobody knows what's going on, because they've got this flashy thief working for them — plus, they always work with "fronts" dressed like Lin in every city, who are captured and then killed before INTERPOL can find out who has hired them as thief stunt doubles. But their secrets are visible.


The Machine (third position) sees everything, including the connections between the number and position two in Prague. Now the Machine Gang just needs to extract the number before the Gutenberg Bible is stolen and Lin's daughter is murdered. We get some pyrotechnic caper moves as Finch, Reese, Shaw and Lin fool everybody into looking the wrong direction while they grab the Bible and the number. Meanwhile, Reese finds the Prague guys' secret hideout and busts some heads before rescuing Lin's daughter.

At the end of the Poe story, Dupin and the Inspector return the Queen's letter to her, unopened. Her secrets are not revealed to the King, nor to the police. Whatever covert actions she's engaged in go unseen and unpunished. Likewise, at the end of this episode, the number is allowed to go free, and unpunished. Once the INTERPOL detective understands that Lin has been forced to commit crimes to save her daughter, he discreetly leaves the key to Lin's cell in her hands.


Lin's crimes, and her identity, remain hidden from the other authorities. We've seen this kind of ending for many numbers in this show. Even numbers who aren't exactly nice guys — like the BitCoin millionaire last episode — are allowed to go free, to reach their destinations.


Another critical theorist, Richard Hull, explains in an essay that Poe's story is actually about strategies designed to elude surveillance. He's interested in why the letter remains unread, despite falling into the hands of so many police, inspectors, and politicians. In a typical detective story, Hull points out, you'd expect the big reveal to be the letter's contents — and the repercussions that the Queen must suffer for them. What's different about Poe's story?


Hull suggests that the letter stays hidden because both the Minister and Dupin take a poetic approach to secrecy, using doubles and psychological tricks done in plain sight. In Dupin's case, conscience is involved too; he doesn't believe he should violate the Queen's privacy. As a result, the letter slips beyond the reach of police surveillance — and, indeed, it is even kept secret from us as readers. Hull concludes that even in a surveillance state, privacy can endure through what he calls "poetic resistance."

Your mind will be blown if you consider that the Machine, the ultimate embodiment of the surveillance state, is also in that third position of poetic resistance. But how can resistance to surveillance come from surveillance? Because the Machine represents surveillance with a conscience. As Finch explained in a previous episode, he designed the Machine to spit out nothing but numbers to ensure that humans and their sense of ethics would always be part of the process of meting out justice. The Machine Gang, the humans, bring poetic resistance to the Machine's mission.


In the auspiciously-titled book Enjoy Your Symptom, theorist Slavoj Žižek revisited Lacan's seminar almost 30 years after it was published. He asked, simply, "Why does a letter always arrive at its destination?" Žižek suggests that the answer goes beyond poetic resistance, because the letter's journey is actually a way of thinking about the repercussions of our acts and words. The letter reaches its destination, but in a transformed state, often with its hidden meanings made manifest to the sender.


In the case of the Queen, the letter only reaches its destination after many harrowing months in the Minister's hands. Before its return, the Queen suffers in fear that whatever she's hiding from the King will be revealed. When the letter comes back to her, both she and it are changed. Though her secrets remain safe, she's been forced to confront the enormity of what it would mean to have them get out.

In Person of Interest, we see this same scenario unfold too. The numbers are generated by the Machine in its capacity as a surveillance device commissioned by the government. But some numbers are delivered to the Machine Gang, and transformed, before they reach their destination. Think of the government as the sender of the numbers. That would mean that their strange journey and return represents the repercussions of creating a surveillance state. The message that those numbers bear, when they return, is this: Total surveillance creates blindness and vulnerability.


Both Lacan and Žižek call this message "the return of the repressed." In one sense, "repressed" just refers to things we don't see, like the Minister not seeing that Dupin has spotted his letter, or government agents not seeing that the Machine is watching them. But for Žižek it also refers to the politically repressed, the people whose lives the government tries to control with surveillance or violence. I think Person of Interest is pretty explicitly dealing with that second meaning too. When you turn people into numbers in the surveillance machine, those numbers are going to return to kick you in the ass. But you'll never see it coming.


So I began by saying that "The Purloined Letter" had sparked a philosophical debate. That debate was partly about the repercussions of language and action. The letter is a small unit of language, and in Poe's story it has this extraordinary power to shape human relationships. It also creates repeated scenarios of secrecy and surveillance.

The question, for philosophers, is whether the letter always does reach its destination. Do our actions always return to us in another form? As a corollary, who benefits from those scenarios of hiding and discovery? Is it the Queen? Dupin? Somebody else, watching from the sidelines?


Nobody has the answer. There are only positions.

Person of Interest has a position on this debate, too. In that show, the number always reaches its destination, and the repressed Machine always returns.


Annalee Newitz is the editor-in-chief of io9 and this is her column. She's also the author of Scatter, Adapt and Remember: How Humans Will Survive a Mass Extinction.


* Lacan deals with many topics in the seminar, most of which I don't go into here — but you can read about the debate it caused in the excellent collection The Purloined Poe, which contains reactions to Lacan's ideas from theory greats like Barbara Johnson and Jacques Derrida.