How does Conan Doyle present Holmes as a complex and unusual character in the first two chapters of "The Sign of Four"?

The Sign of Four is presented by Mary Morstan as a complex case. Holmes, being a complex man, is just the man to help solve it. In the first two chapters, Watson introduces various unusual character traits which will become familiar not just throughout the course of the book, but also in subsequent Sherlock Holmes adventures.

The story begins with Watson observing Holmes taking cocaine. He has been witnessing Holmes doing this three times a...

The Sign of Four is presented by Mary Morstan as a complex case. Holmes, being a complex man, is just the man to help solve it. In the first two chapters, Watson introduces various unusual character traits which will become familiar not just throughout the course of the book, but also in subsequent Sherlock Holmes adventures.

The story begins with Watson observing Holmes taking cocaine. He has been witnessing Holmes doing this three times a day for several months. Drug addiction was much more unusual in 19th-century England than it is today. The reason that Holmes gives for taking cocaine is also unusual; his mind "rebels at stagnation." Holmes needs to keep his mind active in order to solve such complex mysteries and regular injections of cocaine help him to do this. At the very least, he thinks it does.

Conan Doyle also allows us to marvel at Holmes's incredible powers of observation, as displayed in his brilliant deduction about the background history of the pocket watch belonging to Watson. Holmes correctly deduces that the watch once belonged to Watson's alcoholic brother from a simple examination of scratch marks and grooves.

It is here we see another character trait of Holmes that marks him out from the rest of humanity: a certain cold-bloodedness. When Holmes reveals the provenance of Watson's pocket watch, Watson is rather offended. Holmes means no offense; he is merely exercising his capacity for abstract logic to the utmost.

In chapter 2 we see this characteristic of Holmes when he is introduced to the comely Miss Morstan. After she presents Holmes with the facts of the case, Watson immediately observes how attractive the young lady is. Holmes, however, claims not to have noticed as he casually lights a pipe and sits back in his chair.

An exasperated Watson rebukes Holmes, describing him as an "automaton," and a "calculating machine"; indeed, there is something "positively inhuman" about him. Perhaps Watson is being a little harsh; however, we can still accept that Sherlock Holmes is no ordinary human being, as Conan Doyle makes perfectly clear in the first two chapters of The Sign of Four.