Writing it down enforces (some sort of) logic

Jenny quotes Erica Wagner:

Isaac Bashevis Singer wrote for more than four decades on an Underwood portable. For him, his machine was a kind of first editor. “If this typewriter doesn’t like a story, it refuses to work,” he said. “I don’t get a man to correct it since I know if I get a good idea the machine will make peace with me again. I don’t believe my own words saying this, but I’ve had the experience so many times that I’m really astonished. But the typewriter is 42 years old. It should have some literary experience, it should have a mind of its own.”

Hey, I’ve been writing for almost 42 years myself!

More to the point, the Singer quote reminds me of my own experience in doing mathematics. It’s virtually impossible for me to write down a formula with pen on paper unless I understand what the formula means. The act of writing enforces rigor. It makes perfect sense to me that a similar thing would happen to Singer when typing stories.