Did Sherlock Holmes have a character development arc across Arthur Conan Doyle's books?

Question

Often, in a large novel, a character would have a character development arc, which is considered an integral part of writing.

But Sherlock Holmes canon consists mostly of smaller stories.

Was there a cross-story character development arc for Holmes?

Answer 1

One possible case of character development is in "The Adventure of the Three Garridebs" when Holmes, for the first and only time in all the canon, is shown to care for his fellow man. This may be more revealing the character that's always been hidden beneath, rather than a change in character, but from an out-of-universe point of view at least, I think it counts as character development:

"You're not hurt, Watson? For God's sake, say that you are not hurt!"

It was worth a wound - it was worth many wounds - to know the depth of loyalty and love which lay behind that cold mask. The clear, hard eyes were dimmed for a moment, and the firm lips were shaking. For the one and only time I caught a glimpse of a great heart as well as of a great brain. All my years of humble but single-minded service culminated in that moment of revelation.

This is quite a change from the utterly cold, logical, even ruthless man we've seen in Holmes in all the other stories - the man who disdains any distraction from the pursuit of pure reason.

Answer 2

There wasn't much development. Most of the stories are short stories, and they rely upon the relationships established for the series - Holmes as the genius, Watson as the storyteller and the person to whom Holmes explains. And occasionally Lestrade as the failing regular police, to show why Holmes is needed in the setting.

Sir Arthur Conan Doyle did try to get rid of the character; having Holmes murdered by Moriarty, and by telling us that Holmes retired to become a beekeeper in "His Last Bow".

The preface to The Case Book of Sherlock Holmes is telling:

I fear that Mr. Sherlock Holmes may become like one of those popular tenors who, having outlived their time, are still tempted to make repeated farewell bows to their indulgent audiences. This must cease and he must go the way of all flesh, material or imaginary.

So, the main character became stuck in his role early on, to the point that the writer himself considered it monotonous. If Sir Arthur Conan Doyle could have broken this "monotony" by adding character development, he probably would have.