In a recent profile of Robert Caro, David Marchese asks Caro about his practice of planning his books.

I know that when you’re planning your books, you write a couple paragraphs for yourself that explain what the books are about, and then you use those paragraphs as a North Star to guide your writing and outlining.

This, and one additional question, leads Caro to demonstrate how the technique works in practice. How it helps him to tell the right stories and eliminate stories that, though they are interesting or compelling, don’t connect to his “North Star” paragraphs. How it serves as a kind of invisible fence around the province of his subject. Caro explains, vis-à-vis his magisterial Master of the Senate:

Here’s how I boiled that book down: I said that two things come together. It’s the South that raises Johnson to power in the Senate, and it’s the South that says, “You’re never going to pass a civil rights bill.” So to tell that story you have to show the power of the South and the horribleness of the South, and also how Johnson defeated the South. I said, “I can do all that through Richard Russell,” because he’s the Senate leader of the South, and he embodies this absolute, disgusting hatred of black people. I thought that if I could do Russell right, I wouldn’t have to stop the momentum of the book to give a whole lecture on the South and civil rights. What I’m trying to say is that if you can figure out what your book is about and boil it down into a couple of paragraphs, then all of a sudden a mass of other stuff is much simpler to fit into your longer outline.

nytimes.com/interactive/2019/04/01/magazine/robert-caro-working-memoir.html

Clarity is always about choices, or, as the old writer’s dictum goes, “having the guts to cut.” It helps one’s confidence in such cutting to boil things down, to trim along the edges of the shadow cast from a clear North Star.