To read a book in college, it helps to have read a book in high school.Nicholas dames has taught Literature Humanities, Columbia University’s required great-books course, since 1998. He loves the job, but it has changed. Over the past decade, students have become overwhelmed by the reading. College kids have never read everything they’re assigned, of course, but this feels different. Dames’s students now seem bewildered by the thought of finishing multiple books a semester. His colleagues have noticed the same problem. Many students no longer arrive at college—even at highly selective, elite colleges—prepared to read books.This development puzzled Dames...