This article is a response to Robert Darnton's comments on the relations and tensions between intellectual history and the history of books. The author comments on three arguments presented by Darnton. One is that intellectual historians often pay little attention to a question that seems to be of central importance to historians of the book: diffusion. Skinner argues that, to intellectual historians, the wide diffusion of a particular work is not a sure sign of its importance. Conversely, many of the greatest books of the past were not best-sellers. Another point made by Darnton is that intellectual historians often study books that are read and understood only by a small handful of people, a practice that constitutes a form of elitism. Skinner denies the charge of elitism by arguing that intellectual historians also study lesser-known works, and that this criticism can only be made from a philistine viewpoint. Finally, Skinner comments on the issue of the purpose of intellectual activity, defending the position that it plays the role of critically illuminating the moral and political concepts that are nowadays used to construct and appraise our common world.