Dupin's Logic by Jackson Keller

As the first detective murder mystery, Edgar Allen Poe’s short story “The Murder’s in the Rue Morgue” establishes a lot of the conventions and tropes of the genre as a whole. Poe gives us the genius recluse, as well as his intelligent, but ultimately normal, companion and narrator, the ineffective police, and the final reveal of the mystery (Ahem, Doyle you copycat, you). Suspension of disbelief plays a necessary role in these works of fiction. The genius-murder-mystery-solvers pull off a lot of mental feats that most people probably can’t. These feats are part of what makes the stories entertaining; they’re exciting and incredible, but at the same time no so unrealistic as to baffle the audience. SPOILER ALERT: in “Rue Morgue”, an orangutan committed the murder (Do you really need spoiler alerts for stories published in 1841? At what point can I just say whatever I want? What’s the etiquette on that, huh?). While the orangutan murderer is pretty out there in terms of later stories in the genre, Dupin’s (that’s our genius in this one: C. Auguste Dupin) method of solving the crime allows for continued suspension of disbelief. Dupin uses his logic and reasoning to discover how the murderer must have escaped, and what physical capabilities the murderer needed to pull off the crime, analyzing the bodies at the crime scene and their brutal injuries, the noises heard by first responders, and a little tuft of orange hair found in one of the victim’s hands. He deduces that only an orangutan could have pulled off the crime. Pretty far out… but maybe someone could do it with all the evidence Dupin gathers with his skills of observation.

Everything’s fine and dandy, right? NO EVERYTHING IS NOT. I’d like to address a specific trope in the genre that should challenge reader’s suspension of disbelief: mind-reading. Let’s look at a passage from the story:

We were strolling one night down a long dirty street, in the vicinity of the Palais Royal. Being both, apparently, occupied with thought, neither of us had spoken a syllable for fifteen minutes at least. All at once Dupin broke forth with these words:
“He is a very little fellow, that’s true, and would do better for the Theatre des Varietes.”
“There can be no doubt of that,” I replied, unwittingly, and not at first observing (so much had I been absorbed in reflection) the extraordinary manner in which the speaker had chimed in with my meditations. In an instant afterward I recollected myself, and my astonishment was profound.
“Dupin,” said I, gravely, “this is beyond my comprehension. I do not hesitate to say that I am amazed, and can scarcely credit my senses. How was it possible you should know I was thinking of—-?” Here I paused, to ascertain beyond a doubt whether he really knew of whom I thought.
“—-of Chantilly,” said he, “why do you pause? You were remarking to yourself that his diminutive figure unfitted him for tragedy.”
This was precisely what had formed the subject of my reflections. Chantilly was a quondam cobbler of the Rue St. Denis, who, becoming stage-mad, had attempted the role of Xerxes, in Crebillon’s tragedy so called, and been notoriously Pasquinaded for his pains.
“Tell me, for Heaven’s sake,” I exclaimed, “the method–if method there is–by which you have been enabled to fathom my soul in this matter.” In fact, I was even more startled than I would have been willing to express.
“It was the fruiterer,” replied my friend, “who brought you to the conclusion that the mender of soles was not of sufficient height for Xerxes et id genus omne.”
“The fruiterer!–you astonish me–I know no fruiterer whomsoever.”
“The man who ran up against you as we entered the street–it may have been fifteen minutes ago.”
I now remember that, in fact, a fruiterer, carrying upon his head a large basket of apples, had nearly thrown me down, by accident, as we paused from the Rue C—- into the thoroughfare where we stood; but what this had to do with Chantilly I could not possibly understand.
There was not a particle of charlatanerie about Dupin. “I will explain,” he said, “and that you may comprehend all clearly, we will first retrace the course of your meditations, from the moment in which I spoke to you until that of the rencontre with the fruiterer in question. The larger links of the chain run thus–Chantilly, Orion, Dr. Nichols, Epicurus, Stereotomy, the street stones, the fruiterer.”
There are few persons who have not, at some period of their lives, amused themselves in retracing the steps by which particular conclusions of their own minds have been attained. The occupation is often full of interest; and he who attempts it for the first time is astonished by the apparently illimitable distance and incoherence between the starting-point and the goal. What, then, must have been my amazement, when I heard the Frenchman speak what he had just spoken, and when I could not help acknowledging that he spoke the truth. He continued:
“We had been talking of horses, if I remember aright, just before leaving the Rue C—-. This was the last subject we discussed. As we crossed into this street, a fruiterer, with a large basket upon his head, brushing quickly past us, thrust you upon a pile of paving-stones collected at a spot where the causeway is undergoing repair. You stepped upon one of the loose fragments, slipped, slightly strained you ankle, appeared vexed or sulky, muttered a few words, turned to look at the pile, and then proceeded in silence. I was not particularly attentive to what you did; but observation has become with me, of late, a species of necessity.
You kept your eyes upon the ground–glancing, with a petulant expression, at the holes and ruts in the pavement (so that I saw you were still thinking of the stones), until we reached the little alley called Lamartine, which has been paved, by way of experiment, with the overlapping and riveted blocks. Here your countenance brightened up, and, perceiving you lips move, I could not doubt that you murmured the word ‘stereotomy,’ a term very affectedly applied to this species of pavement. I knew that you could not say to yourself ‘stereotomy’ without being brought to think of atomies, and thus of the theories of Epicurus; and since, when we discussed this subject not very long ago, I mentioned to you how singularly, yet with how little notice, the vague guesses of that noble Greek had met with confirmation in the late nebular cosmogony, I felt that you could not avoid casting your eyes upward to the great nebula in Orion, and I certainly expected that you would do so. You did look up; and I was now assured that I correctly followed your steps. But in that bitter tirade upon Chantilly, which appeared in yesterday’s ‘Musee,’ the satirist, making some disgraceful allusions to the cobbler’s change of name upon assuming the buskin, quoted a Latin line about which we have often conversed. I mean the line
Perdidit antiquum litera prima sonum.
I had told you that this was in reference to Orion, formerly written Urion; and, from certain pungencies connected with this explanation, I was aware that you could not have forgotten it. It was clear, therefore, that you would not fail to combine the two ideas of Orion and Chantilly. That you did combine them I saw by the character of the smile which passed over your lips. You thought of the poor cobbler’s immolation. So far, you had been stooping in your gait; but now I saw you draw yourself up to your full height. I was then sure that you reflected upon the diminutive figure of Chantilly. At this point I interrupted your meditations to remark that as, in fact, he was a very little fellow–that Chantilly–he would not do better at the Theatre des Varietes.”

Now if your disbelief is still suspended, I’m going to ask you to recognize how ridiculous this passage is. First of all, 15 minutes is a LONG time to try to follow someone’s train of thought. Most people can’t follow someone’s train of thought at all. Usually if they can, it’s only one thought, of someone who they know very well. Dupin also requires a vast amount of knowledge to guess at every complex thought the narrator contemplates. Our narrator doesn’t exactly think about simple things; we’re talking about constellations and Epicurus. But Dupin is a well-read genius, so we’ll give him this one. However, human thought generally doesn’t act as nicely as it does in this story. First of all, people think about things that are private, or at least not know to everyone else. Our narrator only contemplates intellectual topics at a high level, and his mind doesn’t wander to more mundane topics. External stimuli can change a train of thought without causing any observable external changes in the observer. Many trains of thought could just as easily follow an entirely different pathway; the concept of oranges might just as easily develop into thinking about fruits as into thinking about colors. One wrong guess in which way the train of thought turns ruins Dupin’s trick. Furthermore, Dupin relies on the narrator’s actions to pull off the stunt. Not everyone mumbles “stereotomy” or looks up at the stars, telegraphing their thoughts.

This stunt isn’t just some isolated incident either. Holmes criticizes it when Watson compares him to Dupin, and then in another escapade, Holmes pulls the very same trick. Essentially, the ludicrous mind-reading sequences also constitute one of the tropes of genius-murder-mystery-detective-fiction.

So why bring this all up in the description of a text adventure game anyway? You guessed it; I’ll let you have a try at reading someone’s mind, in a contemporary setting (to even the playing field). I chose to use a text adventure game to present this argument because of their historical notoriety for ridiculous puzzles, along with adventure games in general (refer to the Babel Fish Puzzle from Hitchhiker’s Guide to the Galaxy, 1984; the Gnome puzzle in King’s Quest, 1983; The Disguise from Gabriel Knight, Blood of the Sacred, Blood of the Damned, 1999; or any other personal favorite). While reading someone’s mind in real life is absurd, text adventure developers don’t seem to understand this; they practically require you to read their mind rather than think logically. Therefore, approaching this argument through the medium of text adventure proves quite fitting.

Now before you start your wild goose chase to find out Scottie’s train of thought, allow me to provide some tips
• Scottie’s train of thought won’t wait up for you if you’re goofing off. He’ll keep on thinking no matter what you do, so use your time wisely.
• Observe Scottie’s behavior carefully, much of Dupin’s ability depends on paying close attention to his friend.
• Ponder what your character and Scottie may have talked about recently, this may help you.
• Use the help command to learn more about the game.
• Finally, realize that this is probably an impossible task on your first try. That’s why Dupin’s trick is so ridiculous; it only takes one attempt to perfectly recreate 15 minutes of thought. Have fun, explore the various commands you are able to perform, and don’t take winning too seriously.