minister gave me, too, a great advantage. He is frequently absent from
home all night. His servants are by no means numerous. They sleep at a
distance from their master's apartment, and, being chiefly Neapolitans,
are readily made drunk. I have keys, as you know, with which I can open
any chamber or cabinet in Paris. For three months a night has not
passed, during the greater part of which I have not been engaged,
personally, in ransacking the D---- Hôtel. My honor is interested, and,
to mention a great secret, the reward is enormous. So I did not abandon
the search until I had become fully satisfied that the thief is a more
astute man than myself. I fancy that I have investigated every nook and
corner of the premises in which it is possible that the paper can be
concealed."
"But is it not possible," I suggested, "that although the letter may be
in possession of the minister, as it unquestionably is, he may have
concealed it elsewhere than upon his own premises?"
"This is barely possible," said Dupin. "The present peculiar condition
of affairs at court, and especially of those intrigues in which D---- is
known to be involved, would render the instant availability of the
document--its susceptibility of being produced at a moment's notice--a
point of nearly equal importance with its possession."
"Its susceptibility of being produced?" said I.
"That is to say, of being _destroyed_," said Dupin.
"True," I observed; "the paper is clearly then upon the premises. As for
its being upon the person of the minister, we may consider that as out
of the question."
"Entirely," said the Prefect. "He has been twice waylaid, as if by
footpads, and his person rigorously searched under my own inspection."
"You might have spared yourself the trouble," said Dupin. "D----, I
presume, is not altogether a fool, and, if not, must have anticipated
these waylayings, as a matter of course."
"Not _altogether_ a fool," said G----; "but then he's a poet, which I
take to be only one remove from a fool."
"True," said Dupin, after a long and thoughtful whiff from his
meerschaum, "although I have been guilty of certain doggerel myself."
"Suppose you detail," said I, "the particulars of your search."
"Why, the fact is, we took our time, and we searched _everywhere_. I
have had long experience in these affairs. I took the entire building,
room by room, devoting the nights of a whole week to each. We examined,
first, the furniture of each apartment. We opened every possible drawer;
and I presume you know that, to a properly trained police agent, such a
thing as a _secret_ drawer is impossible. Any man is a dolt who permits
a 'secret' drawer to escape him in a search of this kind. The thing is
_so_ plain. There is a certain amount of bulk--of space--to be accounted
for in every cabinet. Then we have accurate rules. The fiftieth part of
a line could not escape us. After the cabinets we took the chairs. The
cushions we probed with the fine long needles you have seen me employ.
From the tables we removed the tops."
"Why so?"
"Sometimes the top of a table or other similarly arranged piece of
furniture is removed by the person wishing to conceal an article; then
the leg is excavated, the article deposited within the cavity, and the
top replaced. The bottoms and tops of bed-posts are employed in the same
way."
"But could not the cavity be detected by sounding?" I asked.
"By no means, if, when the article is deposited, a sufficient wadding of
cotton be placed around it. Besides, in our case we were obliged to
proceed without noise."
"But you could not have removed--you could not have taken to pieces
_all_ articles of furniture in which it would have been possible to make
a deposit in the manner you mention. A letter may be compressed into a
thin spiral roll, not differing much in shape or bulk from a large
knitting-needle, and in this form it might be inserted into the rung of
a chair, for example. You did not take to pieces all the chairs?"
"Certainly not; but we did better--we examined the rungs of every chair
in the hôtel, and indeed, the jointings of every description of
furniture, by the aid of a most powerful microscope. Had there been any
traces of recent disturbance we should not have failed to detect it
instantly. A single grain of gimlet-dust, for example, would have been
as obvious as an apple. Any disorder in the gluing, any unusual gaping
in the joints, would have sufficed to insure detection."
"I presume you looked to the mirrors, between the boards and the plates,
and you probed the beds and the bedclothes, as well as the curtains and
carpets."
"That, of course; and when we had absolutely completed every article of
furniture in this way, then we examined the house itself. We divided its
entire surface into compartments, which we numbered, so that none might
be missed; then we scrutinized each individual square inch throughout
the premises, including the two houses immediately adjoining, with the
microscope, as before."
"The two houses adjoining!" I exclaimed; "you must have had a great deal
of trouble."
"We had; but the reward offered is prodigious."
"You include the _grounds_ about the houses?"
"All the grounds are paved with brick. They gave us comparatively
little trouble. We examined the moss between the bricks, and found it
undisturbed."
"You looked among D----'s papers, of course, and into the books of the
library?"
"Certainly, we opened every package and parcel; we not only opened every
book, but we turned over every leaf in each volume, not contenting
ourselves with a mere shake, according to the fashion of some of our
police officers. We also measured the thickness of every book-_cover_,
with the most accurate admeasurement, and applied to each the most
jealous scrutiny of the microscope. Had any of the bindings been
recently meddled with, it would have been utterly impossible that the
fact should have escaped observation. Some five or six volumes, just
from the hands of the binder, we carefully probed, longitudinally, with
the needles."
"You explored the floors beneath the carpets?"
"Beyond doubt. We removed every carpet, and examined the boards with the
microscope."
"And the paper on the walls?"
"Yes."
"You looked into the cellars?"
"We did."
"Then," I said, "you have been making a miscalculation, and the letter
is _not_ upon the premises, as you suppose."
"I fear you are right there," said the Prefect. "And now, Dupin, what
would you advise me to do?"
"To make a thorough of the premises."
"That is absolutely needless," replied G----. "I am not more sure that I
breathe than I am that the letter is not at the hôtel."
"I have no better advice to give you," said Dupin. "You have, of
course, an accurate description of the letter?"
"Oh, yes." And here the Prefect, producing a memorandum-book, proceeded
to read aloud a minute account of the internal, and especially of the
external appearance of the missing document. Soon after finishing the
perusal of this description, he took his departure, more entirely
depressed in spirits than I had ever known the good gentleman before.
In about a month afterward he paid us another visit, and found us
occupied very nearly as before. He took a pipe and a chair, and entered
into some ordinary conversation. At length I said:--
"Well, but G----, what of the purloined letter? I presume you have at
last made up your mind that there is no such thing as overreaching the
minister?"
"Confound him, say I--yes; I made the re-examination, however, as Dupin
suggested; but it was all labor lost, as I knew it would be."
"How much was the reward offered, did you say?" asked Dupin.
"Why, a very great deal--a _very_ liberal reward--I don't like to say
how much precisely; but one thing I _will_ say, that I wouldn't mind
giving my individual check for fifty thousand francs to any one who
obtains me that letter. The fact is, it is becoming of more and more
importance every day; and the reward has been lately doubled. If it were
trebled, however, I could do no more than I have done."
"Why, yes," said Dupin drawlingly, between the whiffs of his meerschaum,
"I really--think, G----, you have not exerted yourself--to the utmost in
this matter. You might do a little more, I think, eh?"
"How? in what way?"
"Why, [puff, puff] you might [puff, puff] employ counsel in the matter,
eh? [puff, puff, puff]. Do you remember the story they tell of
Abernethy?"
"No; hang Abernethy!"
"To be sure! hang him and welcome. But, once upon a time, a certain rich
miser conceived the design of sponging upon this Abernethy for a medical
opinion. Getting up, for this purpose, an ordinary conversation in a
private company, he insinuated his case to the physician, as that of an
imaginary individual.
"'We will suppose,' said the miser, 'that his symptoms are such and
such; now, doctor, what would _you_ have directed him to take?'
"'Take!' said Abernethy, 'why, take _advice_, to be sure.'"
"But," said the Prefect, a little discomposed, "_I_ am _perfectly_
willing to take advice, and to pay for it. I would _really_ give fifty
thousand francs to any one who would aid me in the matter."
"In that case," replied Dupin, opening a drawer, and producing a
check-book, "you may as well fill me up a check for the amount
mentioned. When you have signed it, I will hand you the letter."
I was astounded. The Prefect appeared absolutely thunderstricken. For
some minutes he remained speechless and motionless, looking
incredulously at my friend with open mouth, and eyes that seemed
starting from their sockets; then, apparently recovering himself in some
measure, he seized a pen, and, after several pauses and vacant stares,
finally filled up and signed a check for fifty thousand francs, and
handed it across the table to Dupin. The latter examined it carefully,
and deposited it in his pocket-book; then, unlocking an _escritoire_,
took thence a letter and gave it to the Prefect. This functionary
grasped it in a perfect agony of joy, opened it with a trembling hand,
cast a rapid glance at its contents, and then, scrambling and struggling
to the door, rushed at length unceremoniously from the room and from the
house, without having offered a syllable since Dupin had requested him
to fill up the check.
When he had gone, my friend entered into some explanations.
"The Parisian police," he said, "are exceedingly able in their way. They
are persevering, ingenious, cunning, and thoroughly versed in the
knowledge which their duties seem chiefly to demand. Thus, when
G---- detailed to us his mode of searching the premises of the Hôtel
D----, I felt entire confidence in his having made a satisfactory
investigation--so far as his labors extended."
"So far as his labors extended?" said I.
"Yes," said Dupin. "The measures adopted were not only the best of their
kind, but carried out to absolute perfection. Had the letter been
deposited within the range of their search, these fellows would, beyond
a question, have found it."
I merely laughed, but he seemed quite serious in all that he said.
"The measures, then," he continued, "were good in their kind, and well
executed; their defect lay in their being inapplicable to the case and
to the man. A certain set of highly ingenious resources are, with the
Prefect, a sort of Procrustean bed, to which he forcibly adapts his
designs. But he perpetually errs by being too deep or too shallow, for
the matter in hand; and many a schoolboy is a better reasoner than he.
I knew one about eight years of age, whose success at guessing in the
game of 'even and odd' attracted universal admiration. This game is
simple, and is played with marbles. One player holds in his hand a
number of these toys, and demands of another whether that number is even
or odd. If the guess is right, the guesser wins one; if wrong, he loses
one. The boy to whom I allude won all the marbles of the school. Of
course he had some principle of guessing; and this lay in mere
observation and admeasurement of the astuteness of his opponents. For
example, an arrant simpleton is his opponent, and, holding up his closed
hand asks, 'Are they even or odd?' Our schoolboy replies, 'Odd,' and
loses; but upon the second trial he wins, for he then says to himself,
'The simpleton had them even upon the first trial, and his amount of
cunning is just sufficient to make him have them odd upon the second; I
will therefore guess odd;' he guesses odd, and wins. Now, with a
simpleton a degree above the first he would have reasoned thus: 'This
fellow finds that in the first instance I guessed odd, and in the second
he will propose to himself, upon the first impulse, a simple variation
from even to odd, as did the first simpleton; but then a second thought
will suggest that this is too simple a variation, and finally he will
decide upon putting it even as before. I will therefore guess even;' he
guesses even, and wins. Now, this mode of reasoning in the schoolboy,
whom his fellows term 'lucky,' what, in its last analysis, is it?"
"It is merely," I said, "an identification of the reasoner's intellect
with that of his opponent."
"It is," said Dupin; "and, upon inquiring of the boy by what means he
effected the _thorough_ identification in which his success consisted, I
received answer as follows: 'When I wish to find out how wise, or how
stupid, or how good, or how wicked is any one, or what are his thoughts
at the moment, I fashion the expression of my face, as accurately as
possible, in accordance with the expression of his, and then wait to see
what thoughts or sentiments arise in my mind or heart, as if to match or
correspond with the expression.' This response of the schoolboy lies at
the bottom of all the spurious profundity which has been attributed to
Rochefoucauld, to La Bougive, to Machiavelli, and to Campanella."
"And the identification," I said, "of the reasoner's intellect with that
of his opponent depends, if I understand you aright, upon the accuracy
with which the opponent's intellect is admeasured."
"For its practical value it depends upon this," replied Dupin; "and the
Prefect and his cohort fail so frequently, first, by default of this
identification, and secondly, by ill-admeasurement, or rather through
non-admeasurement, of the intellect with which they are engaged. They
consider only their _own_ ideas of ingenuity; and, in searching for
anything hidden, advert only to the modes in which _they_ would have
hidden it. They are right in this much--that their own ingenuity is a
faithful representative of that of _the mass_; but when the cunning of
the individual felon is diverse in character from their own, the felon
foils them, of course. This always happens when it is above their own,
and very usually when it is below. They have no variation of principle
in their investigations; at best, when urged by some unusual
emergency--by some extraordinary reward--they extend or exaggerate their
old modes of _practice_, without touching their principles. What, for
example, in this case of D----, has been done to vary the principle of
action? What is all this boring, and probing, and sounding, and
scrutinizing with the microscope, and dividing the surface of the
building into registered square inches--what is it all but an
exaggeration _of the application_ of the one principle or set of
principles of search, which are based upon the one set of notions
regarding human ingenuity, to which the Prefect, in the long routine of
his duty, has been accustomed? Do you not see he has taken it for
granted that _all_ men proceed to conceal a letter--not exactly in a
gimlet-hole bored in a chair-leg--but, at least, in _some_
out-of-the-way hole or corner suggested by the same tenor of thought
which would urge a man to secrete a letter in a gimlet-hole bored in a
chair leg? And do you not see also, that such _recherché_ nooks for
concealment are adapted only for ordinary occasions, and would be
adopted only by ordinary intellects?--for, in all cases of concealment,
a disposal of the article concealed--a disposal of it in this
_recherché_ manner, is, in the very first instance, presumable and
presumed; and thus its discovery depends, not at all upon the acumen,
but altogether upon the mere care, patience, and determination of the
seekers; and where the case is of importance--or, what amounts to the
same thing in the policial eyes, when the reward is of magnitude--the
qualities in question have _never_ been known to fail. You will now
understand what I meant in suggesting that, had the purloined letter
been hidden anywhere within the limits of the Prefect's examination--in
other words, had the principle of its concealment been comprehended
within the principles of the Prefect--its discovery would have been a
matter altogether beyond question. This functionary, however, has been
thoroughly mystified; and the remote source of his defeat lies in the
supposition that the minister is a fool, because he has acquired renown
as a poet. All fools are poets; this the Prefect _feels_; and he is
merely guilty of a _non distributio medii_ in thence inferring that all
poets are fools."
"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 à parier_,'" replied Dupin, quoting from Chamfort, "'_que
toute idée publique, toute convention reçue, est une sottise, car elle a
convenue au plus grande 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 practical deception; but if the term is of any importance--if
words derive any value from applicability--then 'analysis' conveys, in
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
unusually _untrue_ that the aggregated parts are equal to the whole. In
chemistry, also, the axiom fails. In the consideration of motive it
fails; 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_^2 + _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_^2 + _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.
"I mean to say," continued Dupin, while I merely laughed at his last
observations, "that if the minister had been no more than a
mathematician, the Prefect would have been under no necessity of giving
me this check. I knew him, however, as both mathematician and poet; and
my measures were adapted to his capacity, with reference to the
circumstances by which he was surrounded. I know him as courtier, too,
and as a bold _intrigant_. Such a man, I consider, could not fail to be
aware of the ordinary political modes of action. He could not have
failed to anticipate--and events have proved that he did not fail to
anticipate--the waylayings to which he was subjected. He must have
foreseen, I reflected, the secret investigations of his premises. His
frequent absences from home at night, which were hailed by the Prefect
as certain aids to his success, I regarded only as _ruses_, to afford
opportunity for thorough search to the police, and thus the sooner to
impress them with the conviction to which G----, in fact, did finally
arrive--the conviction that the letter was not upon the premises. I
felt, also, that the whole train of thought, which I was at some pains
in detailing to you just now, concerning the invariable principle of
policial action in searches for articles concealed, I felt that this
whole train of thought would necessarily pass through the mind of the
minister. It would imperatively lead him to despise all the ordinary
_nooks_ of concealment. _He_ could not, I reflected, be so weak as not
to see that the most intricate and remote recess of his hôtel would be
as open as his commonest closets to the eyes, to the probes, to the
gimlets, and to the microscopes of the Prefect. I saw, in fine, that he
would be driven, as a matter of course, to _simplicity_, if not
deliberately induced to it as a matter of choice. You will remember,
perhaps, how desperately the Prefect laughed when I suggested, upon our
first interview, that it was just possible this mystery troubled him so
much on account of its being so _very_ self-evident."
"Yes," said I, "I remember his merriment well. I really thought he would
have fallen into convulsions."
"The material world," continued Dupin, "abounds with very strict
analogies to the immaterial; and thus some color of truth has been given
to the rhetorical dogma, that metaphor, or simile, may be made to
strengthen an argument, as well as to embellish a description. The
principle of the _vis inertiæ_, for example, seems to be identical in
physics and metaphysics. It is not more true in the former, that a large
body is with more difficulty set in motion than a smaller one, and that
its subsequent _momentum_ is commensurate with this difficulty, that it
is in the latter, that intellects of the vaster capacity, while more
forcible, more constant, and more eventful in their movements than those
of inferior grade, are yet the less readily moved, and more embarrassed
and full of hesitation in the first few steps of their progress. Again;
have you ever noticed which of the street signs over the shop doors are
the most attractive of attention?"
"I have never given the matter a thought," I said.