Children's literature charts the makings of the literate imagination. It shows children finding worlds within the book and books in the world. It addresses the changing environments of family life and human growth, schooling and scholarship, publishing and publicity in which children--at times suddenly, at times subtly--found themselves changed by literature. But what is childhood? It is a shifting category that has meaning in relationship to other stages of personal development and family life. Greeks and Romans, Byzantines and Anglo-Saxons, Renaissance and Revolutionary cultures all had clearly defined concepts of the child and, in turn, canons of children's literature. Children are or become, in the words of the 20th-century philosopher Marx Wartofsky, "what they are taken to be by others, and what they come to take themselves to be, in the course of their social communication and interaction with others." So, too, is children's literature: books that are taken into childhood, that foster social communication, and that, in their interaction with their readers, owners, sellers, and collectors, teach and please. In this article, Seth Lerer explores what children have heard and read. Their stories, poems, plays, or treatises may well have been composed with children in mind; or they may have been adapted for readers of different ages. Lerer distinguishes, therefore, between claims that children's literature consists of books written for children and that it consists of those read, regardless of original authorial intention, by children. He concludes that if there is a future to children's literature, it must lie in the artifacts of writing and the place of reading in the home and in the school. To understand the history of children's literature is to understand the history of all forms of literary experience.