Charles Hartshorne, America's foremost process metaphysician, is a rare Godenthusiastic thinker. For more than a half century he has been the major champion of the modal version of the ontological argument for divine existence according to which God exists because necessary existence is part of the definition of God as "that than which no greater can be conceived." If God did not necessarily exist, S/He would not be that which is Unsurpassable. For Hartshome, this does not mean that God cannot surpass Himself/Herself, only that nothing else can. God, for Hartshorne, is in process like everything else.
The book Charles Hartshorne and the Existence of God, by Donald Wayne Viney, is an admirably lucid, readable and accurate explication of Hartshorne's philosophy of God. Its originality consists in an attempt to explain and defend Hartshorne's "global argument" for divine being -a combination of six arguments, which together are supposed to mutually support and make coherent a process view of the Divine. The global argument consists of a version of each of the following theological arguments: the ontological, the cosmological, the design, the epistemic, the moral, and the aesthetic argument, each of which is the subject of a chapter under that title. Viney elucidates these arguments all very well. I have no quarrel with the fidelity of his interpretations (nor, more importantly, has Hartshorne who wrote the preface congratulating the author). Where I do demur is with the thinking of Hartshome himself.
If Saint Anselm's "discovery," according to Hartshorne, is that God necessarily existsif the concept of God is coherently conceivable (Hartshorne admits that it may not be) -Hartshorne's "discovery" (like A.N. Whitehead's) is that God contains potentiality for growth just like everything else in the universe. (This, for Hartshome, removes some of the possible incoherence from the concept.) God is no exception to the metaphysical principle of Creativity according to which all events are both active and passive at the same time. As opposed to classical theists (e.g., Anselm, Aquinas, Descartes, Kant, etc.), who hold that God is Pure Act with no potency for change or creative interaction with anything else,