Summary: Part I, Chapter II: The Science of Deduction

The next day, Watson and Holmes inspect the rooms at 221B Baker Street and move in immediately. Watson, stuck inside due to his health, studies his roommate. Holmes seems quiet and occasionally sinks into a stupor that suggests drug use, though Watson dismisses the idea. Holmes shows great interest in certain topics and discounts others. Watson makes a list of Holmes’s areas of knowledge: poisons, the soils of London, chemistry, sensational literature, and British law. Watson also notices that visitors from different backgrounds call upon Holmes. 

One morning, Watson reads an article that discusses how much an observant person may learn simply by examining everything around him. When Watson ridicules the article, Holmes reveals that he wrote it. Holmes explains that he uses his theories about observation to earn his living as a consulting detective. Holmes’s visitors are clients, and often Holmes solves their problems without even leaving the flat. When Watson expresses disbelief, Holmes explains the deductions that told him that Watson had been in Afghanistan. Watson then mentions his favorite literary detectives, but Holmes disdains them. To change the topic, Watson points out a man walking down the street. Holmes identifies the man as a retired Marines sergeant, and soon the man knocks on their door and hands Holmes a letter.

Analysis: Part I, Chapter II

Through Dr. Watson’s efforts to discover more about Sherlock Holmes in Chapter II, the reader continues to learn about Holmes’s peculiar character traits. Dr. Watson approaches these efforts as a sort of investigation into the mystery of Sherlock Holmes, observing Holmes’s habits and taking notes as a detective would. One reason Watson struggles to understand Holmes is that Holmes never discloses anything personal about himself, a fact that will persist for the duration of the novel. Another reason is Holmes’s unique and often paradoxical nature. Holmes’s fierce activity is punctuated by periods of dormancy and extreme depression. He has a vast store of knowledge in certain areas but is utterly ignorant in others. He seems to have no friends but has many visitors and acquaintances. Holmes’s paradoxical nature is openly symbolized by his violin playing, which Dr. Watson describes as excellent but eccentric and unfocused.

Though Dr. Watson’s efforts to learn Holmes’s profession are largely frustrated, Holmes’s article on the science of deduction reveals Holmes’s method and gives Watson a window into Holmes’s motivations and underlying philosophies. Deductive reasoning is the particular skill Holmes relies on to discover the truth and carry out his work as a consulting detective, but for Holmes personally it is much more than that. Holmes’s statement that “all life is a great chain” shows that Holmes believes deductive reasoning to be nothing less than the key to understanding the entire universe. For Holmes, deductive reasoning allows one to find greater meaning in any given set of facts, elevating it to an artform as much as a science. This confluence of art and science manifests itself in Holmes’s personality, his career, and his love of music, and is a theme that will be revisited time and again.