So what are books good for? My best answer is that books produce knowledge by encasing it. Books take ideas and set them down, transforming them through the limitations of space into thinking usable by others. In 1959, C.P. Snow threw down the challenge of "two cultures," the scientific and the humanistic, pursuing their separate, unconnected lives within developed societies. In the new-media ecology of the 21st century, we may not have closed that gap, but the two cultures of the contemporary world are the culture of data and the culture of narrative. Narrative is rarely collective. It isn't infinitely expandable. Narrative has a shape and a temporality, and it ends, just as our lives do. Books tell stories. Scholarly books tell scholarly stories.