Dag Hammarskjold

Topsoil is a place of digestion. It sucks and chews things into smaller pieces. When it's hungry, it turns grey and stony; when it's thirsty, it opens thousands of cracked lips. Subsoil is more skeletal: it doesn't digest.

It's funny because you know the novel process: you get the drafts, you get the galley, and then you get the galley proofs. You have opportunities to change things all along. But the further along in the process you go, the more careful you have to be in making those changes, and the smaller the changes have to be.