even as before. I will therefore guess even;'--he guesses even, and
wins. Now this mode of reasoning in the schoolboy, whom his fellows
termed '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
Rochefoucault, 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