So many things can go wrong in a passage of prose. The writing can be bloated, self-conscious, academic; these are habits that classic style, which treats prose as a window onto the world, is designed to break. The passage can be cryptic, abstruse, arcane; these are symptoms of the curse of knowledge. The syntax can be defective, convoluted, ambiguous; these are flaws that can be prevented by an awareness of the treelike nature of a sentence.