Markham adopted an attitude of affable forbearance. “You spoke at lunchtime, I believe, of one infallible method of detecting crime. Would you care to divulge this profound and priceless secret to a mere district attorney?”
Vance bowed with exaggerated courtesy.10
“Delighted, I’m sure,” he returned. “I referred to the science of individual character and the psychology of human nature. We all do things, d’ ye see, in a certain individual way, according to our temp’raments. Every human act, no matter how large or how small, is a direct expression of a man’s personality and bears the inev’table impress of his nature. Thus, a musician, by looking at a sheet of music, is able to tell at once whether it was composed, for example, by Beethoven, or Schubert, or Debussy, or Chopin. And an artist, by looking at a canvas, knows immediately whether it is a Corot, a Harpignies, a Rembrandt, or a Franz Hals. And just as no two faces are exactly alike, so no two natures are exactly alike; the combination of ingredients which go to make up our personalities, varies in each individual. That is why, when twenty artists, let us say, sit down to paint the same subject, each one conceives and executes it in a different manner. The result in each case is a distinct and unmistakable expression of the personality of the painter who did it.… It’s really rather simple, don’t y’ know.”
“Your theory, doubtless, would be comprehensible to an artist,” said Markham, in a tone of indulgent irony. “But its metaphysical refinements are, I admit, considerably beyond the grasp of a vulgar worldling like myself.”
“‘The mind inclined to what is false rejects the nobler course,’” murmured Vance, with a sigh.
“There is,” argued Markham, “a slight difference between art and crime.”
“Psychologically, old chap, there’s none,” Vance amended evenly. “Crimes possess all the basic factors of a work of art—approach, conception, technique, imagination, attack, method, and organization. Moreover, crimes vary fully as much in their manner, their aspects, and their general nature, as do works of art. Indeed, a carefully planned crime is just as direct an expression of the individual as is a painting, for instance. And therein lies the one great possibility of detection. Just as an expert aesthetician can analyze a picture and tell you who painted it, or the personality and temp’rament of the person who painted it, so can the expert psychologist analyze a crime and tell you who committed it—that is, if he happens to be acquainted with the person—or else can describe to you, with almost mathematical surety, the criminal’s nature and character.… And that, my dear Markham, is the only sure and inev’table means of determining human guilt. All others are mere guesswork, unscientific, uncertain, and—perilous.”
Throughout this explanation Vance’s manner had been almost casual; yet the very serenity and assurance of his attitude conferred upon his words a curious sense of authority. Markham had listened with interest, though it could be seen that he did not regard Vance’s theorizing seriously.
“Your system ignores motive altogether,” he objected.
“Naturally,” Vance replied, “since it’s an irrelevant factor in most crimes. Every one of us, my dear chap, has just as good a motive for killing at least a score of men as the motives which actuate ninety-nine crimes out of a hundred. And, when anyone is murdered, there are dozens of innocent people who had just as strong a motive for doing it as had the actual murderer. Really, y’ know, the fact that a man has a motive is no evidence whatever that he’s guilty—such motives are too universal a possession of the human race. Suspecting a man of murder because he has a motive is like suspecting a man of running away with another man’s wife because he has two legs. The reason that some people kill and others don’t, is a matter of temp’rament—of individual psychology. It all comes back to that.… And another thing: when a person does possess a real motive—something tremendous and overpowering—he’s pretty apt to keep it to himself, to hide it and guard it carefully—eh, what? He may even have disguised the motive through years of preparation; or the motive may have been born within five minutes of the crime through the unexpected discovery of facts a decade old.… So, d’ ye see, the absence of any apparent motive in a crime might be regarded as more incriminating than the presence of one.”
“You are going to have some difficulty in eliminating the idea of cui bono from the consideration of crime.”
“I daresay,” agreed Vance. “The idea of cui bono is just silly enough to be impregnable. And yet, many persons would be benefited by almost anyone’s death. Kill Sumner, and, on that theory, you could arrest the entire membership of the Authors’ League.”
“Opportunity, at any rate,” persisted Markham, “is an insuperable factor in crime—and by opportunity, I mean that affinity of circumstances and conditions which make a particular crime possible, feasible, and convenient for a particular person.”
“Another irrelevant factor,” asserted Vance. “Think of the opportunities we have every day to murder people we dislike! Only the other night I had ten insuff’rable bores to dinner in my apartment—a social devoir. But I refrained—with consid’rable effort, I admit—from putting arsenic in the Pontet Canet. The Borgias and I, y’ see, merely belong in different psychological categ’ries. On the other hand, had I been resolved to do murder, I would—like those resourceful cinquecenio patricians—have created my own opportunity.… And there’s the rub:—one can either make an opportunity or disguise the fact that he had it, with false alibis and various other tricks. You remember the case of the murderer who called the police to break into his victim’s house before the latter had been killed, saying he suspected foul play, and who then preceded the policemen indoors and stabbed the man as they were trailing up the stairs.”11
“Well, what of actual proximity, or presence—the proof of a person being on the scene of the crime at the time it was committed?”
“Again misleading,” Vance declared. “An innocent person’s presence is too often used as a shield by the real murderer, who is actu’lly absent. A clever criminal can commit a crime from a distance through an agency that is present. Also, a clever criminal can arrange an alibi and then go to the scene of the crime disguised and unrecognized. There are far too many convincing ways of being present when one is believed to be absent—and vice versa.… But we can never part from our individualities and our natures. And that is why all crime inev’tably comes back to human psychology—the one fixed, undisguisable basis of deduction.”
“It’s a wonder to me,” said Markham, “in view of your theories, that you don’t advocate dismissing nine-tenths of the police force and installing a gross or two of those psychological machines so popular with the Sunday Supplement editor.”
Vance smoked a minute meditatively.
“I’ve read about ’em. Int’restin’ toys. They can no doubt indicate a certain augmented emotional stress when the patient transfers his attention from the pious platitudes of Dr. Frank Crane to a problem in spherical trigonometry. But if an innocent person were harnessed up to the various tubes, galvanometers, electromagnets, glass plates, and brass knobs of one of these apparatuses, and then quizzed about some recent crime, your indicat’ry needle would cavort about like a Russian dancer as a result of sheer nervous panic on the patient’s part.”
Markham smiled patronizingly.
“And I suppose the needle would remain static with a guilty person in contact?”
“Oh, on the contr’ry,” Vance’s tone was unruffled. “The needle would bob up and down just the same—but not because he was guilty. If he was stupid, for instance, the needle would jump as a result of his resentment at a seemingly newfangled third-degree torture. And if he was intelligent, the needle would jump because of his suppressed mirth at the puerility of the legal mind for indulging in such nonsense.”
“You move me deeply,” said Markham. “My head is spinning like a turbine. But there are those