To convince others convince yourself first?

Before writing a book, Michel Foucault used to write a draft, 500 or 600 pages of notes and first thoughts. Only when he was done with this first draft, did he start the actual book, meaning going to the libraries doing research and digging into the archives, spending months or years probing his subject. He was satisfied only when the final book was the opposite of the initial draft, when the final text was contradicting, almost point by point, the 500-page draft. Only then he knew his book was finished, when he wasn’t that guy who wrote the draft anymore. After he rewrote himself like he rewrote his draft.