MATHEMATICAL FICTION:

a list compiled by Alex Kasman (College of Charleston)

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The Purloined Letter (1845)
Edgar Allan Poe
(click on names to see more mathematical fiction by the same author)
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Contributed by William E. Emba.

"This is the third and last C. Auguste Dupin mystery. The Prefect of Paris police explains a very delicate situation to Dupin, involving a royal letter whose possession grants its bearer great powers, and whose rightful owner is unable to publicly seek redress. The thief is known, and it is known he keeps the letter handy, yet eighteen months of the most assiduous searching of the thief's residence has failed to locate it. The Prefect then mentions that the reward has gone up considerably, but it's not the money that interests him, it's the principle. Dupin asks for the money, for which he will produce the letter. The Prefect writes Dupin a check, and right then and there, Dupin hands the Prefect the letter.

"Before explaining his solution, Dupin launches into a long spiel about mathematics and the nature of reasoning. In particular, he criticizes the Prefect for attacking the problem along purely mathematical angles, when the thief in question is both mathematician and poet."

Here is the discussion of mathematics. (The rest of the story is also available on-line...reach it by following the link above or below.) I must say that I find it very wrong-headed. In particular, I agree with the very notion that he claims to argue against: it is true that mathematicians must have exceptional skills of reasoning, and these skills extend to topic other than mathematics. Though it is true that individual mathematical topics (algebra, for instance) are limited in application outside of mathematics, the logic involved, understanding implication, the need to be very explicit about assumptions, being able to critically analyze one's own beliefs to determine whether they can be proven with a rigorous argument, and being willing to give them up if such an argument can be constructed against them, these are not to be found only among mathematicians, but any mathematician must have these useful skills. In any case, this is what Poe has to say on the topic:

(quoted from The Purloined Letter)

"But is this really the poet?" I asked. "There are two brothers, I know; and both have attained reputation in letters. The Minister I believe has written learnedly on the Differential Calculus. He is a mathematician, and no poet."

"You are mistaken; I know him well; he is both. As poet and mathematician, he would reason well; as mere mathematician, he could not have reasoned at all, and thus would have been at the mercy of the Prefect."

"You surprise me," I said, "by these opinions, which have been contradicted by the voice of the world. You do not mean to set at naught the well-digested idea of centuries. The mathematical reason has long been regarded as the reason par excellence.

"'Il y a a parier,'" replied Dupin, quoting from Chamfort, "'que toute idee publique, toute convention recue, est une sottise, car elle a convenu au plus grand nombre.' The mathematicians, I grant you, have done their best to promulgate the popular error to which you allude, and which is none the less an error for its promulgation as truth. With an art worthy a better cause, for example, they have insinuated the term 'analysis' into application to algebra. The French are the originators of this particular deception; but if a term is of any importance --if words derive any value from applicability --then 'analysis' conveys 'algebra' about as much as, in Latin, 'ambitus' implies 'ambition,' 'religio' religion or 'homines honesti,' a set of honorable men."

"You have a quarrel on hand, I see," said I, "with some of the algebraists of Paris; but proceed."

"I dispute the availability, and thus the value, of that reason which is cultivated in any especial form other than the abstractly logical. I dispute, in particular, the reason educed by mathematical study. The mathematics are the science of form and quantity; mathematical reasoning is merely logic applied to observation upon form and quantity. The great error lies in supposing that even the truths of what is called pure algebra, are abstract or general truths. And this error is so egregious that I am confounded at the universality with which it has been received. Mathematical axioms are not axioms of general truth. What is true of relation --of form and quantity --is often grossly false in regard to morals, for example. In this latter science it is very usually untrue that the aggregated parts are equal to the whole. In chemistry also the axiom falls. In the consideration of motive it falls; for two motives, each of a given value, have not, necessarily, a value when united, equal to the sum of their values apart. There are numerous other mathematical truths which are only truths within the limits of relation. But the mathematician argues, from his finite truths, through habit, as if they were of an absolutely general applicability --as the world indeed imagines them to be. Bryant, in his very learned 'Mythology,' mentions an analogous source of error, when he says that 'although the Pagan fables are not believed, yet we forget ourselves continually, and make inferences from them as existing realities.' With the algebraists, however, who are Pagans themselves, the 'Pagan fables' are believed, and the inferences are made, not so much through lapse of memory, as through an unaccountable addling of the brains. In short, I never yet encountered the mere mathematician who could be trusted out of equal roots, or one who did not clandestinely hold it as a point of his faith that x squared + px was absolutely and unconditionally equal to q. Say to one of these gentlemen, by way of experiment, if you please, that you believe occasions may occur where x squared + px is not altogether equal to q, and, having made him understand what you mean, get out of his reach as speedily as convenient, for, beyond doubt, he will endeavor to knock you down.

Contributed by Braulio Tavares

A lenghty and deep discussion of the mathematical themes in "The Purloined Letter" can be found in John T. Irwin's "The Mystery to a Solution - Poe, Borges and the Analytic Detective Story" (Baltimore, The Johns Hopkins University Press, 1994). Irwin dissects all the numerical and geometrical ideas behind Poe's story, and discusses in detail the text quoted above, from Chapter 34 on. He also examines the influence of French mathematicians on Poe's own studies (West Point was considerably influenced by French mathematics, through the École Polytechnique). It is an exhausting but ultimately rewarding analysis, if you happen to be a mathematically-oriented Edgar Allan Poe fan.

Contributed by James Bashkin

As far as I can recall, I read this but never quite "got it". I was perhaps 13. So, I enjoyed some of it but was a but frustrated. It looks like there isn't as much to "get" as I had hoped, since the argument seems silly now.

More information about this work can be found at xroads.virginia.edu.
(Note: This is just one work of mathematical fiction from the list. To see the entire list or to see more works of mathematical fiction, return to the Homepage.)

Works Similar to The Purloined Letter
According to my `secret formula', the following works of mathematical fiction are similar to this one:
  1. Description of a New World, Called The Blazing World by Margaret Cavendish
  2. Tigor (aka The Snowflake Constant) by Peter Stephan Jungk
  3. The Gold-Bug by Edgar Allan Poe
  4. Albert's Bridge by Tom Stoppard
  5. The Balloon Hoax by Edgar Allan Poe
  6. Cantor's War by Christopher Anvil
  7. The Name of the Rose by Umberto Eco
  8. Round the Moon by Jules Verne
  9. The Franklin's Tale (in The Canterbury Tales) by Geoffrey Chaucer
  10. Kavanagh by Henry Wadsworth Longfellow
Ratings for The Purloined Letter:
RatingsHave you seen/read this work of mathematical fiction? Then click here to enter your own votes on its mathematical content and literary quality or send me comments to post on this Webpage.
Mathematical Content:
2/5 (6 votes)
..
Literary Quality:
3.28/5 (7 votes)
..

Categories:
GenreMystery,
MotifMath as Cold/Dry/Useless,
Topic
MediumShort Stories, Available Free Online,

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(Maintained by Alex Kasman, College of Charleston)