First an example…
This is the opening paragraph from the story Modern Saint #271 in the collection Slaves of New York by Tama Janowitz:
After I became a prostitute, I had to deal with penises of every imaginable shape and size. Some large, others quite shriveled and pendulous of testicle. Some blue-veined and reeking of Stilton, some miserly. Some crabbed, enchanted, dusted with pearls like the great minarets of the Taj Mahal, jesting penises, ringed as the tail of a raccoon, fervent, crested, impossible to live with, marigold-scented. More and more I became grateful I didn’t have to own one of these appendages.
The question is always: What does your character know well? What was their experience and education, and how does that shape how they perceive the world? I call this the “body of knowledge” and it’s the lens that distorts everything a narrator or character encounters.
Once you know the character’s body of knowledge, you’ll know exactly how they’ll depict the world. A realtor and a doctor never walk into the same house. One will see market value, or improvements done badly. The other will see… mold?
Fitzgerald once wrote that life is best looked at through a single, small window. Body of knowledge is that window.
Another use for body of knowledge is that it allows you to hint at the character’s state of mind. We cherry pick facts that support how we want to see the world and ourselves. In my novel Snuff, for instance, the character Cassie Wright can cite every actor who’s ever died while performing — Tyrone Power, Vic Morrow, Zero Mostel, Sylvia Syms, etc. — because she intends to swallow cyanide during production of a porn movie. Her body of knowledge comforts and enables her. And it hints her intentions to the reader.
We seek out knowledge that confirms our worldview. So body of knowledge doesn’t just shape our perspective, it also reveals our inner life. This is different than large “info dumps” usually found in science fiction. And it’s different than an authority speech such as the one given in My Cousin Vinny or the cerulean blue speech from The Devil Wears Prada or Matt Damon’s bar speech. Whether info dumps or authority speeches, they both work to convince your reader that the character is smart — or that the writer is. Both establish intellectual authority, but that’s not worth much in the internet age as now the rebuttal “what’s your source?” renders facts less universally impressive.
But an interior knowledge based on education and experience will show up in every word of your story. It will shape every perception and action, and the character’s body of knowledge will expose their secret worldview.
That said, as you begin any project, ask yourself what your narrator or character knows. And how will that lens shape how they see the world?
I suppose an overt example would be Patrick Bateman from ‘American Psycho’. His body of knowledge being the clothing people wear, their haircuts, the restaurants they frequent, etc. I only recently discovered that Ellis actually made the clothes combinations in the book actually quite weird. Something that a reader whose savvy with the topic may notice but which is probably gonna go over the heads of most readers.
I have a folder called "Random Characters Talking." If/ when a "character" starts "talking" I write down all the stuff they say. The next step is to find out the context and environment in which the character was talking—which often becomes part of the story.