Lila: An Inquiry into Morals by Robert Pirsig is the follow-up book to Zen and the Art of Motorcycle Maintenance. In this second volume, Pirsig moves beyond the ideas that he illustrates in his first novel to explore these concepts even more deeply. The book is the story of the main character, Phaedrus, a very thinly veiled version of Pirsig himself, sailing up the Hudson river with his newly acquired passenger, Lila. Juxtaposed with the story is Phaedrus's philosophical narrative, as he explains the piece of persuasive literature he is writing.