The Sherlock Holmes stories have been analyzed in so many ways, but the key to their longevity and popularity is the friendship between the Great Detective and the Good Doctor. That relationship provides a model for literary friendships even now.

Friends should contrast

The friendship of Holmes and Watson works because they are so different. Holmes is the genius, who doesn’t run his household on anything like the conventions expected during Victorian times. He’s the cold, unemotional brain, the loner. Watson, on the other hand, has a variety of friends, marries, has compassion and interest in people as a doctor, did his duty in the army. He’s a very typical middle-class Englishman. Readers get two very distinct characters.

As I create characters, I check to make sure all of them, not just the major ones, are somehow different from each other. If I sense two are doing the same job in the story because they have similar personalities, I examine them to see if I need to get rid of one or give one a personality transplant.

A few months ago, I was working on the plots for the next novels after The Truth and Other Strangers. I realized a major character I’d planned to introduce in the second novel just didn’t work any more. I had developed several new characters who did his job for him. As fond as I was of this old character, I ejected him from my story. He wasn’t needed any more.

Friends should be compatible

Literary friends should be distinct but not so different that you can’t believe these characters are friends. Watson gives Holmes some normalcy, a support, and a sounding board for his theories. Holmes gives Watson adventure. The very proper Victorian doctor revels in the excitement of his friend’s escapades. This is clearly illustrated in the short story “The Adventure of Charles Augustus Milverton”. Holmes proposes to break into a professional blackmailer’s house and destroy the items he’s holding over a client. Watson insists on joining Holmes and while standing guard, writes “I thrilled now with a keener zest than I had ever enjoyed when we were defenders of the law instead of its defiers.”

Each character gains something from the other that he doesn’t possess himself. This is true for romantic characters, too. A serious man is drawn to a woman’s humor. Or an outgoing woman is attracted to a thoughtful, introverted man. I’ve seen this work in my own marriage. I’m artistic and my husband is logical, a nuclear engineer. When I run into trouble with a plot, I give him my parameters, and he will come up with a logical progression for the story.

Friends should have flaws

If two characters live in perfect harmony, they will annoy readers, who have yet to find such perfect friends in reality. Watson writes about Holmes’s stranger habits, like firing a gun indoors to make a design of bullet holes in a wall and keeping his unanswered mail stabbed to the mantel. Watson irritates Holmes with concern for his health.

Sometimes, when I create a character I enjoy, I have to make sure I throw in some kind of flaw. Often I just need one character to be irritated by what I like in the first character. So if I have a very outgoing, talkative man, some characters might find him colorful, while others find him a blowhard. Same quality, different perceptions.

What are some literary friendships that served as a model for you?