From an interview with Don DeLillo in the Paris Review (link):
This book is an argument about the future. Who wins the struggle for the imagination of the world? There was a time when the inner world of the novelist—Kafka’s private vision and maybe Beckett’s—eventually folded into the three-dimensional world we were all living in. These men wrote a kind of world narrative. And so did Joyce in another sense. Joyce turned the book into a world with Ulysses and Finnegans Wake. Today, the world has become a book—more precisely a news story or television show or piece of film footage.