A spectre is haunting literature today – the spectre of patacriticism. Nowhere is the threat more evident than in the dog riddle propounded by the late Marx: “Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read.” This book, which explains for the first time what Marx meant, works from two assumptions: 1. That the riddle conceals an allegory about book culture and is addressed to the academic custodians of book culture; and 2. that our explanation is necessarily implicated in the problem posed by the riddle of the dog. It therefore remains to be seen – it is the reader’s part to decide – whether the book is a friend to man or, perhaps like Marx’s riddle, too dark to read.