  Godfrey finds this too restrictive. And so after offering a detailed explanation of the different ways in which one can know of something “what it is” and “that it is,” he writes that just as in knowing material things we move from more confused to less confused knowledge, so it is in the case of our natural knowledge of God. Just as we find that some things are the principal causes of others, and some are governed by others, so we impose the name “God” to signify something in the universe which is the one first cause of everything else and than which nothing greater can be thought. But such nominal knowledge is not enough to prove that what we express by the name “God” exists in reality or “that he is.” Next we may follow Aristotle’s procedure in Physics VII where by eliminating recourse to an infinite regress of moved movers he concludes that one First Mover or God exists. And from the continuous motion of the first mobile sphere Aristotle shows in Physics VIII that God is perpetual and pure act. This tells us that God is in reality, but not what he is in any real sense. In the Metaphysics (Bk XII), continues Godfrey, Aristotle accepts the knowledge “that God is” as proved in the Physics and now proceeds to show that certain perfections are present in God to the preeminent degree. According to Godfrey, Aristotle uses these perfections as quasi-differences and thereby progresses from knowledge “that God is” to knowledge “what he is” by passing from a confused and quasi-generic knowledge to a more determined and quasi-specific knowledge. And so, too, proposes Godfrey, we may reason, for instance, first by knowing him as a substance, then as an incorporeal substance, then as a living and intelligent incorporeal substance. He acknowledges that God does not really fall into any genus or species. Nonetheless, he maintains against Aquinas that we can know “what God is” in some real sense, even though he recognizes that in this life such knowledge will always be imperfect (PB 3.384–86; Wippel, 1981, 108–15).