Chapter 5 TRACES

If you want to solve a crime, call a doctor—better still, a doctor who is a crime writer. Detection, at bottom, is a diagnostic enterprise: like many Victorian intellectual endeavors, medicine and crime-solving seek to reconstruct the past through the minute examination of clues. For if the nineteenth century was about the coming of modern science, it was also about the coming of science of a very particular type: reconstructive fields, like geology, archaeology, paleontology, and evolutionary biology, that let investigators assemble a record of past events through evidentiary traces, often barely discernible, that lingered in the present.

From a single bone, the French naturalist Georges Cuvier could induce the whole of an extinct animal. From ruins unearthed at Troy and at Knossos, the German archaeologist Heinrich Schliemann and the English archaeologist Arthur Evans conjured long-dead civilizations. “The foreteller asserts that, at some future time, a properly situated observer will witness certain events,” Thomas Henry Huxley wrote in 1880; “the clairvoyant declares that, at this present time, certain things are to be witnessed a thousand miles away; the retrospective prophet (would that there were such a word as ‘backteller!’) affirms that so many hours or years ago, such and such things were to be seen. In all these cases, it is only the relation to time which alters—the process of divination beyond the limits of possible direct knowledge remains the same.”

A goal of these new sciences was the creation of narrative—a narrative of things past, often long past, that could be assembled only through the close reading, painstaking analysis, and rigorous chronological ordering of what could be discerned in the present. Huxley evocatively called this process “retrospective prophecy.”

“From a drop of water, a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other,” one of the most famous nineteenth-century passages on retrospective prophecy runs. It continues:

So all life is a great chain, the nature of which is known whenever we are shown a single link of it. Like all the other arts, the Science of Deduction and Analysis is one which can only be acquired by long and patient study….Let the inquirer begin by mastering more elementary problems. Let him, on meeting a fellow-mortal, learn at a glance to distinguish the history of the man, and the trade or profession to which he belongs. Puerile as such an exercise may seem, it sharpens the faculties of observation, and teaches one where to look and what to look for. By a man’s finger-nails, by his coat-sleeve, by his boots, by his trouser-knees, by the callosities of his forefinger and thumb, by his expression, by his shirt-cuffs—by each of these things a man’s calling is plainly revealed.

The author of that passage, which is taken, we learn, from his celebrated essay “The Book of Life,” is none other than Sherlock Holmes, as his very first adventure, A Study in Scarlet, reveals. For in creating Holmes, his fictional “scientific detective,” Conan Doyle was evangelizing as vigorously for late Victorian rationalism as Huxley was doing in his essays and public lectures.*1

Retrospective prophecy underpins both detection and doctoring, for in their modus operandi, the two have much in common. Both often start with a body. Both reason backward, from discernible effect (a clue, a symptom) to covert cause (a culprit, a disease). Both are deeply concerned with questions of identity, and both seek an elusive quarry: a criminal for the detective, a germ or other agent of illness for the doctor. Both bring about solutions through great learning, minute observation, and reasoned, carefully controlled leaps of imagination. Both are inherently moral enterprises, seeking to restore a state of order (safety, health) that has been disrupted. In the detective fiction of the late Victorian period, all these elements are exquisitely combined.

Ultimately, both disciplines seek to answer the most fundamental question there is: What happened? To do so, the investigator must gather evidence, but therein lies a basic challenge: neither detective nor doctor—nor any retrospective prophet—is apt to encounter the evidence in the chronological order in which it was laid down. It was not until the nineteenth century that medicine became fully cognizant of this problem, only then considering the patient’s symptoms to be the last link in a narrative chain. With that conceptual shift, the diagnostic examination began to assume the form we recognize today.

“Throughout the 18th century, doctors based their diagnoses mainly on their patients’ spontaneous verbal communications,” the physician Claudio Rapezzi and his colleagues have written. “As diseases were categorised by symptoms, patients could communicate their symptoms verbally, or even by letter. Thus, doctors could effectively ‘visit’ a patient…by post.” But by the nineteenth century, doctors who wished to discern, identify, and correctly order medical clues had to learn not merely to look directly but to “look feelingly,” as Edmund Pellegrino has written. Precisely this skill was imparted to Conan Doyle by Joseph Bell.

By the end of the century, advances in microscopy had enabled doctors to look more precisely than ever. Likewise for detectives of the period, for whom seeing retrospectively was best accomplished by seeing minutely. “It has long been an axiom of mine that the little things are infinitely the most important,” Holmes says confidently in “A Case of Identity,” a story from 1891. A year later, Bell obliged Conan Doyle by furnishing the introduction to the 1892 edition of A Study in Scarlet. “The importance of the infinitely little is incalculable,” Bell wrote. “Trained as he has been to notice and appreciate minute detail, Dr. Doyle saw how he could interest his intelligent readers by taking them into his confidence, and showing his mode of working. He created a shrewd, quick-sighted, inquisitive man, half doctor, half virtuoso.”

It is noteworthy, too, to recall that Conan Doyle trained as an eye doctor, for the Slater case is crucially about late Victorian ways of seeing—for good and, on balance, for ill. With its focus on identification, and its prejudices rooted in class and ethnicity, the case is at its core about visual diagnosis or, more accurately, misdiagnosis of a prolonged and pernicious kind.

RETROSPECTIVE PROPHECY DID NOT start with the Victorians, of course: the art has its roots deep in antiquity, born of the hunter’s skill at tracking his prey by reading its traces. Before Holmes, one of the finest fictional exponents of this skill was Zadig, the ancient Eastern prince who is the title character of Voltaire’s philosophical novella of 1747. In a passage that was an acknowledged influence on Conan Doyle, Zadig offers a masterly demonstration:

One day, when he was walking near a little wood, he saw one of the queen’s eunuchs running to meet him, followed by several officers, who appeared to be in the greatest uneasiness….

“Young man,” said the chief eunuch to Zadig, “have you seen the queen’s dog?”

Zadig modestly replied: “It is a bitch, not a dog.”

“You are right,” said the eunuch.

“It is a very small spaniel,” added Zadig; “it is not long since she has had a litter of puppies; she is lame in the left forefoot; and her ears are very long.”

“You have seen her, then?” said the chief eunuch, quite out of breath.

“No,” answered Zadig. “I have never seen her, and never knew the queen had a bitch.”…

The chief eunuch had no doubt that Zadig had stolen…the queen’s bitch, so they caused him to be brought before the Assembly of the Grand Desterham, which condemned him to the knout^*2 and to pass the rest of his life in Siberia. Scarcely had the sentence been pronounced, when…the bitch [was] found. The judges were now under the disagreeable necessity of amending their judgment; but they condemned Zadig to pay four hundred ounces of gold for having said that he had not seen what he had seen….Afterwards he was allowed to plead his cause….He expressed himself in the following terms:

“…I saw on the sand the footprints of an animal, and easily decided that they were those of a little dog. Long and faintly marked furrows, imprinted where the sand was slightly raised between the footprints, told me that it was a bitch whose dugs were drooping, and that consequently she must have given birth to young ones only a few days before. Other marks of a different character, showing that the surface of the sand had been constantly grazed on either side of the front paws, informed me that she had very long ears; and, as I observed that the sand was always less deeply indented by one paw than by the other three, I gathered that the bitch belonging to our august queen was a little lame….”

All the judges marvelled at Zadig’s deep and subtle discernment….Though several magi were of opinion that he ought to be burned as a wizard, the king ordered that he should be released from the fine of four hundred ounces of gold to which he had been condemned. The registrar, the bailiffs, and the attorneys came to his house with great solemnity to restore him his four hundred ounces; they kept back only three hundred and ninety-eight of them for legal expenses.

It is clearly no accident that when the name “Zadig” is given a Germanic reading—with “z” pronounced “tz” and “g” pronounced “k,” as it might be uttered by Yiddish-speaking Jews—it becomes “Tzaddik,” the term, rooted in the Hebrew word for “justice,” that denotes a spiritual master who possesses profound wisdom.

The first modern fictional detective, and every inch an heir to Zadig, was Edgar Allan Poe’s cogitating protagonist, the chevalier C. Auguste Dupin. Dupin, who made his debut in 1841 in “The Murders in the Rue Morgue” and returned in “The Mystery of Marie Rogêt” and “The Purloined Letter,” anticipates Holmes in several respects. He is a gentleman—brilliant, aloof, gothic, nocturnal, dissolute. He has a faithful companion who renders the tales of his exploits for the public. He is possessed of observational powers so minute, and a mind so rational, that he can induce a connected chain of contingencies from a single residual clue.

Dupin’s skill at retrospective prophecy—“ratiocination,” Poe calls it—can seem almost clairvoyant, as in a famous scene from “The Murders in the Rue Morgue.” In it, Dupin correctly divines that his friend has been thinking about Chantilly, a petite, stagestruck local cobbler, from the way the friend stumbles in the street after a fruit seller bumps into him. “You were remarking to yourself that his diminutive figure unfitted him for tragedy,” Dupin concludes. “The larger links of the chain run thus—Chantilly, Orion, Dr. Nichol, Epicurus, Stereotomy, the street stones, the fruiterer….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 do better at the Théâtre des Variétés.”

BY 1887, WHEN SHERLOCK HOLMES made his debut, late nineteenth-century scientific method and the late nineteenth-century literary detective were poised for sublime convergence. In Conan Doyle’s hero, the ratiocinative skills exhibited by Dupin would reach their apogee.^*3 “The scientific method made the fictional detective possible and it made him popular,” J. K. Van Dover, an authority on detective literature, has observed. “The detective offered himself as a special model of the new scientific thinker….He promised to combine the most powerful method of thought with a fundamental commitment to traditional ethics (and, as a further attraction, to exercise his method…on the sensational matter of violent crime), and the public embraced him.”

Conan Doyle was not the only crime writer of the period to combine detective and scientist into a single estimable hero. The British writer R. Austin Freeman (1862–1943) married detection and doctoring overtly in the character of John Thorndyke, a physician and crime-solving forensic analyst who starred in novels and stories published between 1907 and 1942. A master of “medico-legal practice,” Thorndyke never traveled without the green canvas-covered box, “only a foot square by four inches deep,” that contained his portable crime laboratory: “rows of little re-agent bottles, tiny test-tubes, diminutive spirit-lamp, dwarf microscope and assorted instruments on the same Lilliputian scale.” It came to his aid at many a crime scene.

But it was Holmes that the reading public embraced above all. His lightning-quick mind, unassailable logic, ironclad ethics, and genius for discerning patterns amid a forest of evidentiary noise equipped him spectacularly for the literary detective’s most vital task: “The narrative of the detective story depends entirely upon [the hero’s] ability to uncover the moral order of his world through a methodical observation and interpretation of its surfaces,” Van Dover has written. “Those actions…must always allow two plausible readings, one erroneous and one true. The first is the easy reading, the one toward which the inertia of our prejudices inclines us;…the second is the hard reading, the one derived from the detective’s thoughtful analysis.”

It was the first reading, with its expedient conclusions and engineered results, that police and prosecutors nearly always pursued in the Slater case. It was the second, rooted in the subtle use of the diagnostic imagination, that Conan Doyle had learned to perform under the master, Joseph Bell.