Editing Sherlock Holmes (section)

==Knowledge and skills==
Shortly after meeting Holmes in the first story, ''A Study in Scarlet'' (generally assumed to be 1881, though the exact date is not given), Watson assesses the detective's abilities:

{{Blockquote|
# Knowledge of Literature&nbsp;– nil.
# Knowledge of Philosophy&nbsp;– nil.
# Knowledge of Astronomy&nbsp;– nil.
# Knowledge of Politics&nbsp;– Feeble.
# Knowledge of Botany&nbsp;– Variable. Well up in [[Atropa belladonna|belladonna]], [[opium]], and poisons generally. Knows nothing of practical gardening.
# Knowledge of Geology&nbsp;– Practical, but limited. Tells at a glance different soils from each other. After walks, has shown me splashes upon his trousers, and told me by their colour and consistence in what [[Geology of London|part of London]] he had received them.
# Knowledge of Chemistry&nbsp;– Profound.
# Knowledge of Anatomy&nbsp;– Accurate, but unsystematic.
# Knowledge of [[Sensation novel|Sensational Literature]]&nbsp;– Immense. He appears to know every detail of every horror perpetrated in the century.
# Plays the violin well.
# Is an expert [[singlestick]] player, boxer, and swordsman.
# Has a good practical knowledge of British law.<ref name="Klinger III pp. 34-35">Klinger III, pp. 34-35—''A Study in Scarlet''</ref>}}

In ''A Study in Scarlet'', Holmes claims to be unaware that the Earth revolves around the Sun since such information is irrelevant to his work; after hearing that fact from Watson, he says he will immediately try to forget it. The detective believes that the mind has a finite capacity for information storage, and learning useless things reduces one's ability to learn useful things.<ref>Klinger III, pp. 32-33—''A Study in Scarlet''</ref> The later stories move away from this notion: in ''[[The Valley of Fear]]'', he says, "All knowledge comes useful to the detective",<ref>Klinger III, p. 650—''The Valley of Fear''</ref> and in "The Adventure of the Lion's Mane", the detective calls himself "an omnivorous reader with a strangely retentive memory for trifles".<ref>Klinger II, p. 1689—"The Adventure of the Lion's Mane"</ref> Looking back on the development of the character in 1912, Conan Doyle wrote that "In the first one, the ''Study in Scarlet'', [Holmes] was a mere calculating machine, but I had to make him more of an educated human being as I went on with him."<ref>Richard Lancelyn Green, "Introduction", ''The Return of Sherlock Holmes'' (Oxford: Oxford University Press, 1993) XXX.</ref>

Despite Holmes's supposed ignorance of politics, in "A Scandal in Bohemia" he immediately recognises the true identity of the disguised "Count von Kramm".<ref name="Klinger I pp. 15-16"/> At the end of ''A Study in Scarlet'', Holmes demonstrates a knowledge of [[Latin]].<ref>Klinger III, p. 202—''A Study in Scarlet''</ref> The detective cites [[Hafez]],<ref>Klinger I, p. 100—"A Case of Identity"</ref> [[Johann Wolfgang von Goethe|Goethe]],<ref>Klinger IIII, p. 282—''The Sign of Four''</ref> as well as [[Flaubert's letters|a letter]] from [[Gustave Flaubert]] to [[George Sand]] in the original French.<ref>Klinger I, p. 73—"The Red-Headed League"</ref> In ''The Hound of the Baskervilles'', the detective recognises works by [[Godfrey Kneller]] and [[Joshua Reynolds]]: "Watson won't allow that I know anything of art, but that is mere jealousy since our views upon the subject differ."<ref>Klinger III, p. 570—''The Hound of the Baskervilles''</ref> In "[[The Adventure of the Bruce-Partington Plans]]", Watson says that "Holmes lost himself in a monograph which he had undertaken upon the Polyphonic [[Motet]]s of [[Lassus]]", considered "the last word" on the subject — which must have been the result of an intensive and very specialized musicological study with no obvious application to the solution of criminal mysteries.<ref>Klinger III, pp. 1333-1334, 1338-1340—"The Adventure of the Bruce-Partington Plans"</ref><ref>{{cite web|url=http://webpages.charter.net/lklinger/lassus.htm|title=Lost in Lassus: The Missing Monograph|last=Klinger|first=Leslie|year=1999|url-status=dead|archive-url=https://web.archive.org/web/20160303174800/http://webpages.charter.net/lklinger/lassus.htm|archive-date=3 March 2016|access-date=27 December 2019}}</ref>

Holmes is a [[cryptanalyst]], telling Watson that "I am fairly familiar with all forms of secret writing, and am myself the author of a trifling monograph upon the subject, in which I analyse one hundred and sixty separate ciphers."<ref>Klinger II, p. 888—"The Adventure of the Dancing Men"</ref> Holmes also demonstrates a knowledge of psychology in "A Scandal in Bohemia", luring Irene Adler into betraying where she hid a photograph based on the premise that a woman will rush to save her most valued possession from a fire.<ref>Klinger I, p. 33—"A Scandal in Bohemia"</ref> Another example is in "[[The Adventure of the Blue Carbuncle]]", where Holmes obtains information from a salesman with a wager: "When you see a man with whiskers of that cut and [[The Sporting Times|the 'Pink 'un']] protruding out of his pocket, you can always draw him by a bet&nbsp;... I daresay that if I had put 100 pounds down in front of him, that man would not have given me such complete information as was drawn from him by the idea that he was doing me on a wager."<ref>Klinger I, p. 216—"The Adventure of the Blue Carbuncle"</ref>

[[Maria Konnikova]] points out in an interview with [[D. J. Grothe]] that Holmes practises what is now called mindfulness, concentrating on one thing at a time, and almost never "multitasks". She adds that in this he predates the science showing how helpful this is to the brain.<ref>{{cite web|url=http://www.pointofinquiry.org/maria_konnikova_how_to_think_like_sherlock_holmes/|title=How to Think Like Sherlock Holmes|last1=Konnikova|first1=Maria|website=Point of Inquiry|publisher=Center for Inquiry|access-date=23 July 2017|archive-date=19 December 2018|archive-url=https://web.archive.org/web/20181219211946/http://www.pointofinquiry.org/maria_konnikova_how_to_think_like_sherlock_holmes|url-status=dead}}</ref>

===Holmesian deduction===
[[File:Abbe-03.jpg|thumb|upright|alt=Colour illustration of Holmes bending over a dead man in front of a fireplace|Sidney Paget illustration of Holmes examining a corpse for "[[The Adventure of the Abbey Grange]]"]]

Holmes observes the dress and attitude of his clients and suspects, noting skin marks (such as tattoos), contamination (such as ink stains or clay on boots), emotional state, and physical condition in order to deduce their origins and recent history. The style and state of wear of a person's clothes and personal items are also commonly relied on; in the stories, Holmes is seen applying his method to items such as walking sticks,<ref>Klinger III, pp. 387-392—''The Hound of the Baskervilles''</ref> pipes,<ref>Klinger I, pp. 450-453—"The Yellow Face"</ref> and hats.<ref>Klinger I, pp. 201-203—"The Adventure of the Blue Carbuncle"</ref> For example, in "A Scandal in Bohemia", Holmes infers that Watson had got wet lately and had "a most clumsy and careless servant girl". When Watson asks how Holmes knows this, the detective answers:

{{Blockquote|It is simplicity itself&nbsp;... my eyes tell me that on the inside of your left shoe, just where the firelight strikes it, the leather is scored by six almost parallel cuts. Obviously they have been caused by someone who has very carelessly scraped round the edges of the sole in order to remove crusted mud from it. Hence, you see, my double deduction that you had been out in vile weather, and that you had a particularly malignant boot-slitting specimen of the London slavey.<ref>Klinger I, p. 9—"A Scandal in Bohemia"</ref>}}

In the first Holmes story, ''A Study in Scarlet'', Dr. Watson compares Holmes to [[C. Auguste Dupin]], Edgar Allan Poe's fictional detective, who employed a similar methodology. Alluding to an episode in "[[The Murders in the Rue Morgue]]", where Dupin determines what his friend is thinking despite their having walked together in silence for a quarter of an hour, Holmes remarks: "That trick of his breaking in on his friend's thoughts with an apropos remark&nbsp;... is really very showy and superficial."<ref>Klinger III, p. 42—''A Study in Scarlet''</ref> Nevertheless, Holmes later performs the same 'trick' on Watson in "[[The Adventure of the Cardboard Box|The Cardboard Box]]"<ref>Klinger I, pp. 423-426—"The Cardboard Box"</ref> and "[[The Adventure of the Dancing Men]]".<ref>Klinger II, pp. 864-865—"The Adventure of the Dancing Men"</ref>

Though the stories always refer to Holmes's intellectual detection method as "[[Deductive reasoning|deduction]]", Holmes primarily relies on [[abductive reasoning|abduction]]: [[Inference|inferring]] an explanation for observed details.<ref name="Bird">{{Cite book |url=https://books.google.com/books?id=yMDWLq2FdrIC|title=Oxford studies in epistemology|editor1=Tamar Szabo Gendler |editor-first2=John |editor-last2=Hawthorne |first=Alexander |last=Bird |chapter=Abductive Knowledge and Holmesian Inference |page=11 |isbn=978-0-19-928590-7 |date=27 June 2006|publisher=OUP Oxford }}</ref><ref>{{harvnb|Sebeok|Umiker-Sebeok|1984|pp=19–28, esp. p. 22}}</ref><ref>{{cite book |title=Fact and feeling: Baconian science and the nineteenth-century literary imagination |page=214 |first=Jonathan |last=Smith |year=1994 |publisher=Univ of Wisconsin Press |url=https://books.google.com/books?id=hFn1Zx_desIC |isbn=978-0-299-14354-1 |access-date=29 September 2020 |archive-date=19 February 2024 |archive-url=https://web.archive.org/web/20240219042335/https://books.google.com/books?id=hFn1Zx_desIC |url-status=live }}</ref> "From a drop of water," he writes, "a logician could infer the possibility of an [[Atlantic Ocean|Atlantic]] or a [[Niagara Falls|Niagara]] without having seen or heard of one or the other."<ref>Klinger III, p. 40—''A Study in Scarlet''</ref> However, Holmes does employ deductive reasoning as well. The detective's guiding principle, as he says in ''The Sign of Four'', is: "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."<ref>{{cite web |last=Bennett|first=Bo|title=Pseudo-Logical Fallacies |url=https://www.logicallyfallacious.com/logicalfallacies/Pseudo-Logical-Fallacies |website=Logicallyfallacious.com |publisher=Logically Fallacious |access-date=31 July 2020 |archive-url=https://archive.today/20200731172256/https://www.logicallyfallacious.com/logicalfallacies/Pseudo-Logical-Fallacies |archive-date=31 July 2020 |url-status=live}}</ref>

Holmes follows [[Sir Isaac Newton]]'s rule of ''"hypotheses non fingo"'', for instance commenting in "[[A Scandal in Bohemia]]": "It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." 

Despite Holmes's remarkable reasoning abilities, Conan Doyle still paints him as fallible in this regard (this being a central theme of "[[The Adventure of the Yellow Face|The Yellow Face]]").<ref>Klinger I, pp. 449-471—"The Yellow Face"</ref>

===Forensic science===
[[File:Mikroskop-seibert hg.jpg|thumb|right|upright|alt=See caption|19th-century Seibert microscope]]

Though Holmes is famed for his reasoning capabilities, his investigative technique relies heavily on the acquisition of hard evidence. Many of the techniques he employs in the stories were at the time in their infancy.<ref>{{cite encyclopedia|url=https://www.britannica.com/topic/Sherlock-Holmes-Pioneer-in-Forensic-Science-1976713|title=Sherlock Holmes: Pioneer in Forensic Science|encyclopedia=Encyclopaedia Britannica|access-date=20 December 2019|archive-date=20 December 2019|archive-url=https://web.archive.org/web/20191220224925/https://www.britannica.com/topic/Sherlock-Holmes-Pioneer-in-Forensic-Science-1976713|url-status=live}}</ref><ref name=":4" />

The detective is particularly skilled in the analysis of [[trace evidence]] and other physical evidence, including latent prints (such as footprints, hoof prints, and shoe and tire impressions) to identify actions at a crime scene,<ref>''A Study in Scarlet'', "[[The Adventure of Silver Blaze]]", "The Adventure of the Priory School", ''The Hound of the Baskervilles'', "[[The Boscombe Valley Mystery]]"</ref> using tobacco ashes and cigarette butts to identify criminals,<ref>"[[The Adventure of the Resident Patient]]", ''The Hound of the Baskervilles''</ref> utilizing [[questioned document examination|handwriting analysis]] and [[graphology]],<ref>"[[The Adventure of the Reigate Squire|The Reigate Squires]]", "The Man with the Twisted Lip"</ref> comparing [[Typewriter|typewritten]] letters to expose a fraud,<ref>Klinger I, pp. 99-100—"A Case of Identity"</ref> using gunpowder residue to expose two murderers,<ref>Klinger I, p. 578—"The Reigate Squires"</ref> and analyzing small pieces of human remains to expose two murders.<ref>Klinger I, pp. 438-439—"The Cardboard Box"</ref>

Because of the small scale of much of his evidence, the detective often uses a magnifying glass at the scene and an [[optical microscope]] at his Baker Street lodgings. He uses [[analytical chemistry]] for [[blood residue]] analysis and [[toxicology]] to detect poisons; Holmes's home chemistry laboratory is mentioned in "[[The Adventure of the Naval Treaty|The Naval Treaty]]".<ref>Klinger I, p. 670—"The Naval Treaty"</ref> [[Ballistics]] feature in "The Adventure of the Empty House" when spent bullets are recovered to be matched with a suspected murder weapon, a practice which became regular police procedure only some fifteen years after the story was published.<ref>Klinger II, p. 814—"The Adventure of the Empty House"</ref>

Laura J. Snyder has examined Holmes's methods in the context of mid- to late-19th-century criminology, demonstrating that, while sometimes in advance of what official investigative departments were formally using at the time, they were based upon existing methods and techniques. For example, fingerprints were proposed to be distinct in Conan Doyle's day, and while Holmes used a thumbprint to solve a crime in "[[The Adventure of the Norwood Builder]]" (generally held to be set in 1895), the story was published in 1903, two years after [[Henry Classification System|Scotland Yard's fingerprint bureau]] opened.<ref name=":4">{{cite journal|last=Snyder|first=Laura J.|year=2004|title=Sherlock Holmes: scientific detective|journal=Endeavour|volume=28|issue=3|pages=104–108|doi=10.1016/j.endeavour.2004.07.007|pmid=15350761}}</ref><ref>Klinger II, pp. 860-863</ref> Though the effect of the Holmes stories on the development of forensic science has thus often been overstated, Holmes inspired future generations of forensic scientists to think scientifically and analytically.<ref>{{Cite web |last=Schwartz |first=Roy |date=2022-05-20 |title=Opinion: The fictional character who changed the science of solving crime |url=https://www.cnn.com/2022/05/20/opinions/sherlock-holmes-father-of-modern-forensic-science-schwartz/index.html |access-date=2022-05-21 |website=CNN |language=en |archive-date=21 May 2022 |archive-url=https://web.archive.org/web/20220521182548/https://www.cnn.com/2022/05/20/opinions/sherlock-holmes-father-of-modern-forensic-science-schwartz/index.html |url-status=live }}</ref>

==={{anchor|Disguise}}Disguises===
Holmes displays a strong aptitude for acting and disguise. In several stories ("[[The Sign of Four]]", "[[The Adventure of Charles Augustus Milverton]]", "[[The Man with the Twisted Lip]]", "[[The Adventure of the Empty House]]" and "[[A Scandal in Bohemia]]"), to gather evidence undercover, he uses disguises so convincing that Watson fails to recognise him. In others ("[[The Adventure of the Dying Detective]]" and "[[A Scandal in Bohemia]]"), Holmes feigns injury or illness to incriminate the guilty. In the latter story, Watson says, "The stage lost a fine actor&nbsp;... when [Holmes] became a specialist in crime."<ref>Klinger I, p. 30—"A Scandal in Bohemia"</ref>

[[Guy Mankowski]] has said of Holmes that his ability to change his appearance to blend into any situation "helped him personify the idea of the English eccentric chameleon, in a way that prefigured the likes of [[David Bowie]]".<ref name=":254">{{Cite web |last=Schurr |first=Maria |date=15 March 2021 |title=Hauntings, Dystopia and the English Outsider in Albion's Secret History |url=https://www.popmatters.com/guy-mankowski-albions-secret-history |access-date=30 July 2021 |website=Pop Matters |archive-date=30 July 2021 |archive-url=https://web.archive.org/web/20210730162312/https://www.popmatters.com/guy-mankowski-albions-secret-history |url-status=live }}</ref>

===Agents===
Until Watson's arrival at Baker Street, Holmes largely worked alone, only occasionally employing agents from the city's underclass. These agents included a variety of [[informants]], such as Langdale Pike, a "human book of reference upon all matters of social scandal",<ref>Klinger II, p. 1545—"The Adventure of the Three Gables"</ref> and Shinwell Johnson, who acted as Holmes's "agent in the huge criminal underworld of London".<ref>Klinger II, p. 1456—"The Adventure of the Illustrious Client"</ref> The best known of Holmes's agents are a group of street children he called "the [[Baker Street Irregulars]]".<ref>Klinger III, p. 305—''The Sign of Four''. These "street Arabs" also appear briefly in ''A Study in Scarlet'' and "The Adventure of the Crooked Man".</ref><ref>{{Cite web|url=https://arthurconandoyle.co.uk/character/the-baker-street-irregulars-and-billy-the-page|title=The Baker Street Irregulars and Billy The Page|last=Merritt|first=Russell|website=The Official Conan Doyle Estate Ltd.|access-date=27 December 2019|archive-date=27 December 2019|archive-url=https://web.archive.org/web/20191227071330/https://arthurconandoyle.co.uk/character/the-baker-street-irregulars-and-billy-the-page|url-status=live}}</ref>

==={{anchor|Weapons and martial arts}}Combat===
[[File:British Army Mark III Model of 1872.JPG|thumb|alt=Long-barreled revolver with a black handle|British Army (Adams) Mark III, the type probably carried by Watson]]

====Pistols====
Holmes and Watson often carry pistols with them to confront criminals—in Watson's case, his old service weapon (probably a Mark III [[Beaumont–Adams revolver|Adams revolver]], issued to British troops during the 1870s).<ref name="Guns & Ammo">{{cite web|url=http://archives.gunsandammo.com/content/guns-sherlock-holmes|title=The Guns of Sherlock Holmes|access-date=27 April 2012|url-status=dead|archive-url=https://web.archive.org/web/20121114030405/http://archives.gunsandammo.com/content/guns-sherlock-holmes |archive-date=14 November 2012}}</ref> Holmes and Watson shoot the eponymous hound in ''The Hound of the Baskervilles'',<ref>Klinger III, p. 589—''The Hound of the Baskervilles''</ref> and in "The Adventure of the Empty House", Watson [[pistol-whip]]s Colonel [[Sebastian Moran]].<ref>Klinger II, pp. 805-806—"The Adventure of the Empty House"</ref> In "[[The Problem of Thor Bridge]]", Holmes uses Watson's revolver to solve the case through an experiment.

====Other weapons====
As a gentleman, Holmes often carries a stick or cane. He is described by Watson as an expert at [[singlestick]],<ref name="Klinger III pp. 34-35"/> and uses his cane thrice as a weapon.<ref>See "[[The Red-Headed League]]", "[[The Adventure of the Illustrious Client]]", and "[[The Adventure of the Speckled Band]]".</ref> In ''A Study in Scarlet'', Watson describes Holmes as an expert swordsman,<ref name="Klinger III pp. 34-35"/> and in "The ''Gloria Scott''", the detective says he practised [[fencing]] while at university.<ref name="Klinger I p. 502"/> In several stories ("[[A Case of Identity]]", "The Red-Headed League", "[[The Adventure of the Six Napoleons]]"), Holmes wields a [[Crop (implement)|riding crop]], described in the latter story as his "favourite weapon".<ref>Klinger II, p. 1050—"The Adventure of the Six Napoleons"</ref>

====Personal combat====
[[File:The Adventure of the Solitary Cyclist 03.jpg|thumb|upright|Holmes outfighting Mr Woodley in "[[The Adventure of the Solitary Cyclist|The Solitary Cyclist]]"|alt=Holmes fighting]]
The detective is described (or demonstrated) as possessing above-average physical strength. In "[[The Adventure of the Yellow Face|The Yellow Face]]", Holmes's chronicler says, "Few men were capable of greater muscular effort."<ref>Klinger I, p. 449—"The Yellow Face"</ref> In "[[The Adventure of the Speckled Band]]", Dr. Roylott demonstrates his strength by bending a fire poker in half. Watson describes Holmes as laughing and saying, {{"'}}If he had remained I might have shown him that my grip was not much more feeble than his own.' As he spoke he picked up the steel poker and, with a sudden effort, straightened it out again."<ref>Klinger I, p. 243—"The Adventure of the Speckled Band"</ref>

Holmes is an adept [[Bare-knuckle boxing|bare-knuckle]] fighter; "[[The Adventure of the Gloria Scott|The ''Gloria Scott'']]" mentions that Holmes boxed while at university.<ref name="Klinger I p. 502"/> In [[The Sign of the Four|''The Sign of Four'']], he introduces himself to McMurdo, a [[Professional boxing|prize fighter]], as "the [[Amateur boxing|amateur]] who fought three rounds with you at Alison's rooms on the night of your benefit four years back". McMurdo remembers: "Ah, you're one that has wasted your gifts, you have! You might have aimed high if you had joined the fancy."<ref>Klinger III, pp. 262-263—''The Sign of Four''</ref> In "The Yellow Face", Watson says: "He was undoubtedly one of the finest boxers of his weight that I have ever seen."<ref>Klinger I, pp. 449-450—"The Yellow Face"</ref> In "The Solitary Cyclist", Holmes visits a country [[pub]] to make enquiries regarding a certain Mr Woodley which results in violence. Mr Woodley, Holmes tells Watson,<ref name="Klinger II p. 915">Klinger II, p. 915—"The Solitary Cyclist"</ref>

{{blockquote|...&nbsp;had been drinking his beer in the tap-room, and had heard the whole conversation. Who was I? What did I want? What did I mean by asking questions? He had a fine flow of language, and his adjectives were very vigorous. He ended a string of abuse by a vicious backhander, which I failed to entirely avoid. The next few minutes were delicious. It was a straight left against a slogging ruffian. I emerged as you see me. Mr. Woodley went home in a cart.<ref name="Klinger II p. 915"/>}}

Another character subsequently refers to Mr Woodley as looking "much disfigured" as a result of his encounter with Holmes.<ref>Klinger II, p. 916—"The Solitary Cyclist"</ref>

In "[[The Adventure of the Empty House]]", Holmes tells Watson that he used a [[Japanese martial arts|Japanese martial art]] known as [[baritsu]] to fling Moriarty to his death in the [[Reichenbach Falls]].<ref>Klinger II, p. 791—"The Adventure of the Empty House"</ref> "Baritsu" is Conan Doyle's version of [[bartitsu]], which combines [[jujitsu]] with boxing and [[Canne de combat|cane fencing]].<ref>{{cite web|url=http://www.bartitsu.org/index.php/2010/10/the-mystery-of-baritsu-1958/|title=The Mystery of Baritsu|website=The Bartitsu Society|url-status=dead|archive-url=https://web.archive.org/web/20181130121805/http://www.bartitsu.org/index.php/2010/10/the-mystery-of-baritsu-1958/|archive-date=30 November 2018|access-date=27 December 2019}}</ref>