Rollover Information
About the Series Schedule The Archive Learning Resources The American Collection Home Search Shop
The Hound of the Baskervilles
The Forum Links + Bibliography Teacher's Guide Russell Baker Story Synopsis Who's Who Novel to Film Essays + Interviews Masterpiece Theatre The Hound of the Baskervilles
Essays + Interviews [imagemap with 8 links]
1 2 3 4 Essays + Interviews Subsections

Through the Magnifying Glass
by Richard K. Ho

There's the scarlet thread of murder running through the colourless skein of life, and our duty is to unravel it, and isolate it, and expose every inch of it.
     -- Sherlock Holmes in A Study in Scarlet

A mysterious figure, cloaked in a long dark overcoat, arrives at the scene of a crime. In the deep recesses of his pockets, he carries two items: a simple tape measure and a magnifying glass with a rounded lens. His only other tool is his mind.

Pacing about the room, the stranger quietly hunts for invisible clues between motes of dust and particles of dirt. Sight, smell, touch... all of his senses are called into service, not a single one neglected. Every faculty is devoted to observation and assimilation. The confident manner in which he carries out his investigations suggests an intense, almost obsessive intellect.

The evidence is gathered and systematically analyzed. His focus is impenetrable, his technique infallible. The result is inevitable. Within the hour, the case is cracked. The unsolvable crime is solved. The mysterious stranger unveils the solution with a triumphant flourish, then promptly exits the scene, leaving dozens of professional police officers scratching their heads.

The stuff of fiction? Yes.

For nearly two centuries, characters such as C. Auguste Dupin and Sherlock Holmes have captivated readers with their unparalleled intellects and incomparable crime-solving ability. The genre of crime fiction had come into its own in the nineteenth century, amidst a time of great intellectual advancement. Thanks to the influences of the Enlightenment and the Industrial Revolution, advances in science, technology, and rational thought began to find their way into contemporary literature. Victorian writers such as Edgar Allan Poe and Arthur Conan Doyle incorporated these modern ideas into their fictional works, lending the credibility of science to the practical tasks of criminal detection and investigation.

Thus was established the model of the scientist-detective. Poe's short story, "The Murders in the Rue Morgue" (1841), introduced the brilliant but introverted Dupin to the world, and Conan Doyle's A Study in Scarlet (1887) was the inaugural adventure of the renowned Sherlock Holmes. Each detective displays a remarkable penchant for observation, analysis, and logical deduction, and each chooses to apply his skill to the unraveling of criminal acts. These were the pioneers who paved the way for the convergence of science, criminology, and literature.

back to top

Literary Tradition

The face of science in English popular literature of the nineteenth century was an unenviable one. The craft of Daedalus seemed inherently united with the folly of Icarus.
     -- J. K. Van Dover

It has been remarked that "one of the frequent aims of literary criticism itself... is to trace a work back to its originary ideas or principles" (Martin 34). As such, the detective writings of Poe and Conan Doyle can be traced to the intellectual innovations brought on by the Enlightenment and the Industrial Revolution, which inevitably began to find expression in nineteenth century Victorian literature.

Enlightenment writers like Voltaire and Rousseau popularized the application of reason and rational thought, while the Industrial Revolution brought about advances in all aspects of scientific knowledge, from technology to medicine to chemistry. In the beginning, the literary reaction to this wave of scientific and intellectual advancement was one of cautious skepticism, if not downright rejection. The revolutionary theories of Charles Darwin and other scientists were attacked by many as an affront to the entrenched dogmas of Christianity -- for these traditionalists, "devotion to an empirical method meant abandonment of traditional pieties" (Van Dover 37). This aversion was based in part on a pervasive fear regarding the implications of science on the very notion of humanity. In the eyes of the religion's supporters, the advancements in science and medicine were seen as humanity's attempt to impinge on the authority of God, and could only lead to disastrous consequences. Writers like Mary Shelley and Robert Louis Stevenson captured the fears and uncertainties of society and gave them creative expression in works like Frankenstein (1818) and Dr. Jekyll and Mr. Hyde (1886). Those stories were hugely popular, in part because they reflected "an understandable suspicion of a way of thinking that had, within the century, first refuted the biblical time scale and then contradicted Genesis's account of the origin of species" (Van Dover 37). The creation of monsters became the literal manifestation of the dangers inherent in the pursuit of forbidden knowledge, and each of the scientists responsible for these monstrosities was painted as "an anti-humanist heretic," obsessive, unstable and misguided (Van Dover).

Of course, such feelings were hardly universal, and the rising current of nineteenth century scientific thought was gaining both strength and acceptance. The fears of the earlier half of the century were transformed into a budding "utilitarian confidence in the powers of man," as advances in technology and medicine began to have perceptible positive impacts on ordinary lives (Van Dover 37-8). The image of the mad scientist in popular literature was gradually replaced by a model of the scientist as hero and protagonist, which reflects the trend towards a more cerebral society:

In the modern world, when the days of hand-to-hand combat, of monsters and dragons have passed, and when... the problems confronting human beings are increasingly those of knowledge and cognition, the appropriate hero would seem to be the analyst, the detective, the individual who is able to penetrate deceptive appearances and to cut through reams of contradictory evidence and conflicting testimony to arrive at the truth. (Nygaard 226)

However, while a new conception of the fictional scientist was beginning to take shape, the literature of the period remained slow in abandoning its previous reluctance to embrace the rise of science:

Victorian novelists generally failed to celebrate the accomplishments of the scientists and few -- George Eliot being the outstanding exception -- even attempted to understand and to portray their methods and their motives (Van Dover 38).

Still, Eliot's The Lifted Veil provided a strong case for the exploration of science in literature, and the genre of detective fiction was on the very edge of the horizon.

back to top

Sherlock Holmes's Methodology

The famous detective of Baker Street is similar in many ways to his predecessor Dupin. Like Poe's hero, Holmes employs the power of the scientific method in his efforts to unravel crimes. However, unlike Dupin -- who was described as having a scientific mind -- Conan Doyle's detective seems to possess a greater deal of pure scientific knowledge, though much of it is obtained as an amateur. As Stamford remarks to Watson, "his studies are very desultory and eccentric, but he has amassed a lot of out-of-the-way knowledge which would astonish his professors" (Conan Doyle 7).

To this extensive knowledge base, Holmes adds a genuine love for science, "a passion for definite and exact knowledge," which Stamford finds even "a little too scientific for my tastes" (Conan Doyle 8). Some critics point out that Conan Doyle "deliberately introduced his hero in an explicitly scientific setting... in the laboratory of St. Bartholomew's Hospital," where he is surrounded by "retorts, test-tubes, and little Bunsen lamps" (Van Dover 40-1). Indeed, the reader's first impression of Holmes is that of an ecstatic chemist who has just found a test for bloodstains -- the enthusiasm with which he expounds on this discovery, which he describes as "the most practical medico-legal discovery for years," is both humorous and infectious. And even in this moment of personal triumph, his thought is directed towards his ultimate task -- the detection of crime: "Had this test been invented, there are hundreds of men now walking the earth who would long ago have paid the penalty of their crimes" (Conan Doyle 9-10). The achievements of Holmes in the field of forensics are significant, and carry weight even outside the realm of fiction: "Indeed, modern forensic scientists often admit Holmes's influence upon their profession" (Van Dover 42).

Many critics have pointed to Holmes's mastery of chemistry as the most prominent element of concrete scientific discourse in the story: "It is the clearest witness to his proficiency in a hard science, and Conan Doyle carefully cultivates a sense of Holmes's mastery here. Repeated references to the laboratory bench which Holmes maintains at 221 B Baker Street serve this end" (Van Dover 41).

With such periodic allusions to the science of the non-fictional world, the scientific nature of Holmes's work is given a measure of credibility. As for the validity of the conclusions themselves? Holmes's lines of reasoning, evident in statements such as these, seem to be founded on sound logic:

"...When a fact appears to be opposed to a long train of deductions, it invariably proves to be capable of bearing some other interpretation." (Conan Doyle 62)

"...By the method of exclusion, I had arrived at this result, for no other hypothesis would meet the facts." (Conan Doyle 124)

"...There is a strong family resemblance about misdeeds, and if you have all the details of a thousand at your finger ends, it is odd if you can't unravel the thousand and first. "(Conan Doyle 19-20)

"...It is a mistake to confound strangeness with mystery. The most commonplace crime is often the most mysterious, because it presents no new or special features from which deductions may be drawn... These strange details, far from making the case more difficult, have really had the effect of making it less so." (Conan Doyle 63)

How does Holmes come to these conclusions? His tool of choice is a combination of observation and deduction. In his magazine article entitled "The Book of Life" -- the very same article that incited the skepticism of Watson -- Holmes explained in detail "how much an observant man might learn by an accurate and systematic examination of all that came in his way" (Conan Doyle 18). The word "systematic" is key, for it legitimizes what skeptics like Watson consider a form of mind reading. For an individual trained in the tasks of observation and analysis, all inferences would be "as infallible as so many propositions of Euclid" (Conan Doyle 18). Holmes calls this mode of investigation the "Science of Deduction," and in his explanation he invokes the familiar notion of the chain of causality, made up of individual and interconnected links: "So all life is a great chain, the nature of which is known whenever we are shown a single link of it" (Conan Doyle 18-9). In his observations, he is aided by nothing more than the simplest of tools, relying almost exclusively on the faculties of his mind. At the crime scene in A Study in Scarlet, he "trotted noiselessly about the room, sometimes stopping, occasionally kneeling, and once lying flat upon his face," with nothing but "a tape measure and a large round magnifying glass" in hand (Conan Doyle 32). Yet the simplicity of his methods is deceiving, for even "Sherlock Holmes's smallest actions were all directed towards some definite and practical end" (Conan Doyle 33). No detail is spared by his keen eye, and every detail carries a significant clue.

back to top

Observation... and Deduction

Two deep wheel ruts were found in the mud -- until the previous night, it had not rained for a week...
A cab must have been there the previous night.

The marks of the horse's hoofs were visible, the outline of one of which was far more clearly cut than the other three...
The horse drawing the cab bore three old shoes, and one new one on his off foreleg.

In the dirt outside the house, the tracks of two men are visible, nearly destroyed beneath the heavier tracks of the police constables...
The victim and the murderer arrived together during the night -- one of them wore square-toed boots, the other small elegant boots.

The man wearing the square-toed boots had a particularly long stride...
The man in question was over six feet tall.

A peculiar type of ash was found on the floor of the crime scene...
One of the men smoked a Trichinopoly cigar.

Blood was found all over the floor, but the victim has no visible wounds...
The blood came from the murderer, who was a robust and ruddy-faced man.

A sour smell could be detected on the victim's lips...
Poison was the murder weapon.

The German word "Rache" written on the wall did not exhibit properties characteristic of German handwriting...
The writer was not German, and the sign was intended to throw the police off the track.

A ring was found near the body of the victim...
Love and revenge were the motives of the murder. The murderer evidently used the ring to remind the victim of a woman, and dropped it at the scene.

In the words of Holmes himself: "I am simply applying to ordinary life a few of those precepts of observation and deduction which I advocated in that article" (Conan Doyle 35).

Holmes also recognized the value of the reverse process of analysis -- induction, or backward reasoning:

"...Most people, if you describe a train of events to them, will tell you what the result would be. They can put those events together in their minds, and argue from them that something will come to pass. There are few people, however, who, if you told them a result, would be able to evolve from their own inner consciousness what the steps were which led up to that result." (Conan Doyle 123)

Along with Dupin, Holmes is one of those rare individuals capable of constructing a chain of causality based on a final result. The process, he admits, is not intuitive: "In the every-day affairs of life it is more useful to reason forwards, and so the other comes to be neglected. There are fifty who can reason synthetically for one who can reason analytically" (Conan Doyle 122-3). However, with much practice, an individual can improve their skill to the point of being able to utter remarks such as, "You have been in Afghanistan, I perceive" (Conan Doyle 9).

The train of reasoning ran:

"...Here is a gentleman of a medical type, but with the air of a military man. Clearly an army doctor then. He has just come from the tropics, for his face is dark, and that is not the natural tint of his skin, for his wrists are fair. He has undergone hardship and sickness, as his haggard face says clearly. His left arm has been injured. He holds it in a stiff and unnatural manner. Where in the tropics could an English army doctor have seen much hardship and got his arm wounded? Clearly in Afghanistan." (Conan Doyle 20-1)

As Watson so earnestly remarks to Holmes, "You have brought detection as near an exact science as it ever will be brought in this world" (Conan Doyle 36).

back to top

Literary Analysis Of A Study In Scarlet

Over the years, Sherlock Holmes has emerged as the model of the fictional heroic scientist. With his practical application of observation and deduction to the noble cause of detection, he provides the perfect counterpoint to the early Victorian aversion to science, and proof that "science is not the begetter of monsters or of fantastic heresies; it is a normal instrument routinely applied in the moral crises of everyday life" (Van Dover 38-9). Indeed, morality seems to play a significant role in Holmes's motivation -- while Poe's hero was spurred on by the desire for pure and abstract truth, Conan Doyle's hero is driven by the desire to reveal wrong and do what is right. In effect, Holmes "proclaimed a new moral dimension of scientific approach;" in his efforts to unravel crime, he "devotes himself to restoring moral intelligibility to his world" (Van Dover 40).

And yet, Sherlock Holmes owes a large part of his popularity to his personal imperfections and peculiarities, his "memorably eccentric character" (Van Dover 47). He has a cranky side which reveals itself whenever the discussion turns towards his inferior colleagues in the detective business, such as Gregson and Lestrade. "Gregson," he proclaims, "is the smartest of the Scotland Yarders... he and Lestrade are the pick of a bad lot" (Conan Doyle 24). His disdain for the inadequacies of these detectives can be interpreted as a sign of arrogance -- but in the case of Holmes, the self-confidence is certainly justified. His skill is unparalleled, and he laments the lack of truly perplexing challenges for his abilities:

"...No man lives or has ever lived who has brought the same amount of study and of natural talent to the detection of crime which I have done. And what is the result? There is no crime to detect, or, at most, some bungling villainy with a motive so transparent that even a Scotland Yard official can see through it." (Conan Doyle 22)

Conan Doyle even goes so far as to insert a criticism of Dupin into Holmes's tirade against incompetence. When Watson innocently remarks that, "You remind me of Edgar Allan Poe's Dupin," and "I had no idea that such individuals did exist outside of stories," Holmes proceeds to refute the comparison:

"Now, in my opinion, Dupin was a very inferior fellow. That trick of his of breaking in on his friends' thoughts with an apropos remark after a quarter of an hour's silence is really very showy and superficial. He had some analytical genius, no doubt; but he was by no means such a phenomenon as Poe appeared to imagine." (Conan Doyle 21)

However, it should be noted that the criticism contains no actual remarks on Dupin's technique itself -- Holmes merely takes issue with his "superficial" application of induction to impress his friend. Indeed, the passage seems to convey a tone of playful teasing. While the methods of the two detectives were certainly distinct -- Dupin's use of induction and creative intuition versus Holmes's use of empirical observation and deduction -- Conan Doyle evidently respected Poe's creation, as well as his position as a trailblazer in the genre of detective literature.

The eccentric character of Sherlock Holmes has other unique manifestations. Though he is not a "withdrawn, nocturnal creature like Poe's Dupin," he certainly has moments of personal isolation and reflection (Van Dover 47). His laboratory is his safe haven, a place where he can explore the unlimited possibilities of his scientific tendencies. And yet, Holmes is not a man singularly possessed by science. And, as many critics have noted, the two most visible signs of Holmes's unusual habits are his addiction to cocaine and his love of the violin:

Within the walls of his famous suite at 221B Baker Street, he balances his laboratory bench with Bohemian furnishings, his precise methodology with negligent habits... Holmes's Bohemian habits concretize him as an individual -- he is not simply a type of the scientist -- and they argue that even an extreme advocate of the empirical scientific method... need not be consumed by the pursuit of his profession. (Van Dover 48)

These decidedly unscientific habits provide a sort of equalizing influence, making Holmes a more realistic and human character. The violin provides proof that "artistic impulse... coexists with Holmes's scientific character" (Van Dover 48).

There have been some criticisms regarding the absolute validity of the science that appears in the tales of Sherlock Holmes. Many critics point out that the references to Holmes's scientific skills -- his ability to trace footsteps, his ability to distinguish between tobacco ashes -- exist without any real discussion of their implementation:

These scientific achievements exist more as assertions than as practices. Conan Doyle does not... devote pages of technical dissertation to the original and verifiable methods of his scientific detective. Rather, he contents himself with Holmes's allusions to laboratories and monographs, claims to scientific exactness, and occasional exercises with the magnifying lens and the tape measure. (Van Dover 42)

Additionally, many of Holmes's conclusions are often "only pseudo-scientific -- as when Holmes deduces intelligence from hat size" (Van Dover). And yet, these same critics point out that for the purposes of Conan Doyle's writing -- which, by all accounts, is directed towards the entertainment of the audience -- the casual references to science are enough. "In fiction, though not in lectures to working men, a 'general sense' of the power of the scientist is sufficient" (Van Dover 42). The focus of detective literature remains on the unraveling of crime -- though science is the primary tool of detectives like Holmes, it need not be the primary focus of the story. Regardless of the specificity of his scientific achievements, Holmes has successfully broken down the barriers imposed by Victor Frankenstein and Henry Jekyll, and has emerged as "the heroic anti-type of the anti-heroic type of the scientist in nineteenth century literature" (Van Dover 49).

back to top

Closing The Case

What result, then, has ensued? What impression have I made upon your fancy?
     -- C. Auguste Dupin, The Murders in the Rue Morgue

The observations have been made, the conclusions have been drawn. Through an investigation of the available evidence -- using the inductions of Dupin and the deductions of Holmes -- the facts have been laid bare. Science does indeed play a prominent role in the adventures of these fictional detectives. As for the true extent of that role? Unfortunately, the case on that may never be closed. For over a century, critics have questioned the validity of Poe's cold, logic hero, given the author's well-known tendencies toward the mystical and the imaginative. They've pointed out the holes and inadequacies in Sherlock Holmes's knowledge of hard science. In short, they've challenged the credibility of these detectives as scientists.

And yet, the tools and skills employed by the two detectives are founded upon valid principles of logic and reason. The relationship between the distinct philosophies of Dupin and Holmes has even been compared to another pair of innovators from the annals of history:

Dupin described his approach as a combination of the skills of the poet and the mathematician, skills whose essential nature normally removes them from direct applicability in the practical world. Sherlock Holmes's debt to Dupin was certainly real, but in this respect it is like that of Aristotle, the great scientist, to Plato, another great poet-mathematician. The Platonic tradition in detection continued... Its method -- ratiocination -- remained the esoteric gift of particular geniuses. Holmes's scientific method... was, like Aristotle's, empirical, depending upon investigations into the matter of the mundane world and resulting in synthetic conclusions regarding the nature of that matter. (Van Dover 43-4)

Regardless of the extent to which science is elaborated upon in the writings of Poe and Conan Doyle, its presence in the philosophies of Dupin and Holmes is unmistakable, and undeniable. And despite any doubts that have been raised regarding the role of science in detective literature, the status of Dupin and Holmes as the archetypes of the scientifically inclined detective-hero remains unchallenged.

This essay has been excerpted from a paper of the same name, subtitled The Role of Science in Nineteenth Century Detective Literature, which Richard K. Ho wrote for Professor John Picker's "Literature and Science in the 19th Century" seminar at Harvard University in the fall of 2001. Our thanks to Richard K. Ho for permission to publish his work.

back to top


Conan Doyle, Arthur. A Study in Scarlet, Oxford University Press, 1999.

Martin, Terry J. "Detection, Imagination, and the Introduction to 'The Murders in the Rue Morgue,'" Modern Language Studies, Providence, RI, Fall 1989, 19(4):31-45.

Nygaard, Loisa. "Winning the Game: Inductive Reasoning in Poe's 'Murders in the Rue Morgue,'" Studies in Romanticism, Boston, MA, Summer 1994, 33(2):223-54.

Poe, Edgar Allan. "The Murders in the Rue Morgue," Edgar Allan Poe: Poetry, Tales, & Selected Essays, Literary Classics of the United States, New York, NY, 1984. pp. 397-431.

Van Dover, J. K. "Huxley, Holmes, and the Scientific Detective," The Baker Street Journal: an Irregular Quarterly of Sherlockiana, Hanover, PA, December 1988, 38(4):240-41.

Van Dover, J. K. "The Lens and the Violin: Sherlock Holmes and the Rescue of Science," Clues:a Journal of Detection, Bowling Green, OH, Fall-Winter 1988, 9(2):37-51.

Essays + Interviews:
Now Comes the Mystery... | The Lure of the Moor
Arthur Conan Doyle | Through the Magnifying Glass

Essays + Interviews | Novel to Film | Who's Who | Story Synopsis
Russell Baker | Teacher's Guide | Links + Bibliography | The Forum

Home | About The Series | The American Collection | The Archive
Schedule & Season | Feature Library | eNewsletter | Book Club
Learning Resources | Forum | Search | Shop | Feedback

WGBH Logo PBS logo


Masterpiece is sponsored by: