The next week, I might say, "I can summarize this course in two words: expand and contract!"
Later, in that same class period, I might say, "Content and Form!"
And so on.
My goal is to one day be able to walk into the first day of class, say only two words, and walk away, never to be seen again. Then I'll check back with them 25 years later and see if they got it.
Lately, I've been saying these two words: Attention and Memory.
They're not sufficient, but good writing must utilize them. That is, good writing will command your attention and impress its important points into your memory. It's not good writing unless you can remember something important about it several years later.
John Medina, author of Brain Rules, writes about the use of "hooks" in lectures and writing. The term "hooks" is common in the world of pop music. It's the idea that a catchy melody or phrase will stick in your mind like a fish hook, causing you to hum it in the elevator. It won't leave your head. It's sticky. It's the McDonald's theme song that forces you to unconsciously pull up to the drive through when you're not really hungry.
Writers can, however, use them for less nefarious purposes. They can pull you in for an important idea, not just a lard burger. And then, after you've read their work, you somehow remember it for ever.
This is, I think, accomplished most effectively through image, anecdote, and story. The kind of ditty that carries the important idea inside of it like a piggy bank carries pennies. You pick it up and shake it, and out come the goods.
Would we still read William James today if he had called his theory of consciousness "The perception of metaphysical coherence in transitory neural processes" instead of The Stream of Consciousness?
Would anybody remember anything from Plato's Republic without the Allegory of the Cave and the Parable of the Coins, not to mention his depiction of the tower of philosopher-kings?
What if Jesus had said, "The transcendent deity's conception of justice will grow from an infinitesimal inkling into an expansive network of highly-visible, earthly manifestations," instead of "The Kingdom of God is like a mustard seed."
Those are all hooks. They command your attention by appealing to imagery and stories, and they stick in your brain. Later, when you retrieve these simple images and shake them a bit, the ideas fall out.
Images and stories are highly effective and efficient storage devices for meaning. Facts and figures and long passages come in and go out. People forget 90% of what they hear (see Brain Rules). Only images and stories have a good chance to survive.