Perhaps the most famous ""argument"" in history is that of St. Anselm, called the ""ontological."" Intended to prove the existence of God, Anselm's reasoning was that God's existence was both possible and necessary to explain the world around him, and therefore God did exist: ""what may be, and must be, is."" Despite its obvious drawback of arguing in a circle, Anselm's argument has had an enormous effect on the history of western thought from the twelfth century on. The present work is a collection representative of the most recent thought on Anselm's position. The first part reproduces the pertinent part of Anselm's Proslogion, and seven chapters are then devoted to an analysis and critique, by authors as diverse as Gaunilo and Barth, of the classic position. The second part, by means of eleven essays, traces the course of the argument in recent philosophy, and the contributors include Bertrand Russell, E. E. Harris, Norman Malcolm, and Charles Hartshorne. On the whole, this is a well organized and unified collection directed to a scholarly, and quite circumscribed, audience.