Immortality and the Existence of God: Reformulating the Arguments of Plato, Anselm, and Goedel defends a modern version of Plato's argument for the immortality of the soul. The self is essentially conscious and hence essentially living. It is therefore "deathless" and cannot receive death. But then, it also cannot become something else, nor can it be destroyed, since that would be receiving death also. So, the self or immortal, and immaterial. The book then considers materialist theories of the mind and rejects them. It formulates an argument from introspection which the author believes establishes substance dualism.

The argument for immortality and the Ontological Argument for the existence of God are parallel in that attempt to establish the existence of necessary beings. Since immortality makes sense within a theistic context, the second half of the book defends a version of Goedel's Ontological Argument for God's existence, utilizing experience of the moral good and that mutual entailment of the attributes of God to argue that these attributes, including necessary existence, are logically coherent.

In the final chapter, the author uses the central arguments in the book to support accounts of the afterlife from those who have had near-death experiences.