Philosophical Literature
This is, quite simply, a self-help novel promoting Socrates' Zen-like philosophy as a cure for unhappiness. It mostly consists of two men talking about ideas on how to live life. Dan seeks to implement those ideas, and that he eventually finds unreasonable happiness is meant to show us that we, too, would find it were we to adopt the same strategies. We're given pages and pages and of Socrates' detailed explanations of exactly what the nature of the peaceful warrior is.
The novel is also the chief product in the real Dan Millman's line of multiple other books, seminars, audio programs, exotic adventure trips, and other goods and services, many of them featuring the charismatic Socrates. This might seem a little cynical: is this book just a pill in paper form?
But you could argue that all authors, whether of the self-help movement or held to be canonical great masters, are, in some sense, simply saying, "Here's my vision of the world; read it, and you'll be a little more like me."