Gregory of Nyssa discerned that Arianism erred because it “defines God’s being by its having no beginning, rather than by its having no end . . . . If they must divine eternity, let them reverse their doctrine and find the 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.”

Gregory is here overturning the tragic metaphysics behind Arianism.