Gregory of Nyssa identifies Arianism as a form of tragic metaphysics.  They go astray because they “define God’s being by its having no beginning, rather than by its having no end . . . . If they must divide eternity, let them reverse their doctrine and find that mark of deity in endless futurity . . . ; let them guide their thinking by what is to come and is real in hope rather than by what is past and old.”

Against the Arians, Gregory insists that it’s precisely because the Logos acts and suffers and breaks the boundary of death that He proves Himself to be God.

An eschatological ontology, that.  Jenson adds: “Aristotle’s and Plato’s divinity is the stillness for which moving things long; the being of Gregory’s God is that he keeps things moving.  To be God is always to be open to and always to open a future, transgressing all past-imposed conditions.”