“The reader is expected to quarrel with much that is said in this part of the book. He is likely to feel that much has been exaggerated and much ignored. But this is not an authoritative textbook. It is a book of thoughts, and it does not shy away from half-truths so long as they seem to hint at a new approach and help to formulate new questions. “To illustrate a principle,” says Bagehot, “you must exaggerate much and you must omit much.