The first ten pages are a whirlwind intro to what he's going to be talking about in detail the rest of the book: twelve examples of how books took shape, from author's notes and manuscript through the printed copies within the authors' lives. He picks these 12 for reasons of interest, and there is a wide range of experience from 1591 through the 1970s (though all are white men). There's a balance here - some might even say a contradiction - between the seeming science, the black/white right/wrongness of sound editorial method, and the places where judgement is called for and there is no one right answer.