If you read many mystery stories, you'll note a couple sub-genres: Cozy and Hard-boiled. Agatha Christie's Miss Marple is a little old lady who collects clues in her knitting bag and solves the mystery with her razor-trap mind. Conversely, Raymond Chandler's Philip Marlowe sticks his nose where it isn't wanted and gets out of trouble with hard fists and a hot gat. Now that we've got that out of the way, I have a rhetorical question:
Is Sherlock Holmes a cozy detective or a hard-boiled detective?
The answer is not as obvious as you might think. In 2009 friends complained about all the fisticuffs of Robert Downey, Jr. in the Sherlock Holmes movie, because they thought it improper for a cozy detective to be busting heads. At first, I was inclined to agree. But that my agreement was predicated upon impressions created by Jeremy Brett, Basil Rathbone and a parade of similar screen depictions.
When I reflected upon the Arthur Conan Doyle stories I'd read the impression became less clear. Yes, he fills his pipe, catalogs cigar ashes, and plays the violin--cozy behaviors. But he also goes haring off with revolver in hand. When Sherlock Holmes springs the trap on his quarry, he is likely to subdue him physically.
Sherlock Holmes is both a cozy detective and a hard-boiled detective. And he is neither.
It is useful to reflect upon the reason for this. Arthur Conan Doyle published the first Sherlock Holmes story in 1887. Agatha Christie and Raymond Chandler were not yet born. The cozy and hard-boiled categories did not exist until well after Sherlock Holmes was established in the public mind.
This is not true of the film treatments with with we are familiar. The screen adaptations are written and the performances are interpreted much later with well defined cozy/hard-boiled categories in mind. We've seen cozy elements imposed upon the film treatments that are only latent in the canon.
By way of analogy, before the boffins distinguished between six-legged insect and eight-legged arachnids, people could use the word "bug" in a way that perfectly equivocated the two categories. The Sherlock Holmes of the canon similarly equivocates the categories of cozy and hard-boiled detectives.