Philosophical naturalism, according to which philosophy is continuous with the natural sciences, has dominated the Western academy for well over a century; but Michael Rea claims that it is without rational foundation, and that the costs of embracing it are surprisingly high. The first part of World Without Design aims to provide a fair and historically informed characterization of naturalism. Rea then argues compellingly to the surprising conclusion that naturalists are committed to rejecting realism about material objects, materialism, and perhaps realism about other minds. This conclusion is striking, largely because naturalism is often simply identified with materialism, and the remaining two theses are ones that naturalists very typically want to endorse. Rea goes on to examine two alternative research programs: intuitionism and supernaturalism, and argues for the conclusion that intuitionism, under certain circumstances, is self-defeating. World Without Design offers a provocative challenge to philosophical orthodoxy. It will make uncomfortable reading for many philosophers.