Compare God’s doing something to his power to act. JOST argues that we can have no precise concept of God where the first is distinct from the second, since we have no distinct concept of God except as pure act and thus as already operative. The only sense in which there is a subject of divine activity is
a.) In the understated sense that subsistent acting is the source of acting.
b.) In the sense of “God” as the transcendence of divine attributes. This is the sense of God unknowable to us, i.e. the sense that in our mode of understanding, any one thing known about God need not include all things true about him.
So the notion of God as pure act demands that the divine essence creates. This is not because we visualize some divine subject compelled by his being to create, and this is precisely because there is no divine subject of acting, whether compelled or free. Said another way, there is no intrinsically unrealized divine power to act, or subject of acting, that stands in need of a determining cause to explain how action occurred, but only, at most, the divine essence in its transcendence of any fact predicated of God, whether action or inaction. To have a subject apart from action, with voluntary activity or inactivity as accident, is peculiar to spiritual or material creation.
Complementary to this is what Thomas calls, perhaps infelicitously, “God not having a real relation to the world.” The argument is that creation as creation is something not mutually dependent with God, and since correlatives are mutually dependent (per Aristotle’s account in Categories c. 7), God and creation are not mutual correlatives. This is not just because of divine non-dependance on creation, but also because created subjects are not relative to a divine subject.
Just Thomism 