This is a study of the collaborative creation behind literary works that are usually considered to be written by a single author. Although most theories of interpretation and editing depend on a concept of single authorship, many works are actually developed by more than one author. Stillinger examines case histories from Keats, Wordsworth, Coleridge, Mill, and T.S. Eliot, as well as from American fiction, plays, and films, demonstrating that multiple authorship is a widespread phenomenon. He shows that the reality of how an author produces a work is often more complex than is expressed in the romantic notion of the author as solitary genius. The cumulative evidence revealed in this engaging study indicates that collaboration deserves to be included in any account of authorial achievement.