Agamben ( Opus Dei: An Archaeology of Duty ) concludes his book with a summary of the argument of Ernst Benz, who claimed that a metaphysics of will took the place of classic metaphysics of being first in Neoplatonism and then in Christian Trinitarian theology. For Neoplatonists, it is through will that the One hypostasizes itself, “unfolding itself toward itself” and so constituting itself as mind. Plotinus thus concludes that “will and substance must in itself coincide necessarily with being itself.” Even before Christians coined homoousios, Neoplatonists were describing the hypostasization of being in “a homoousian way” (127, quoting Benz).

This necessarily implies a “dynamic conception” of the divine being, in which “being is ‘mobilized’ and put in movement.” This has its roots already in Aristotle, but it comes into its own in Neoplatonic and Christian thought in the view that “the movement of being is . . . not produced in itself and by nature but implies an energeia and and incessant ‘putting-to-work,’ that is, it is thought as an ergon that refers to the effectuation on the part of a subject that will be, in the first and last instance, identified with the will” (128).

Agamben seems unaware that he is describing Arian theology here, the claim that the Son is begotten not by nature but by will. Yet, he is not entirely wrong about orthodoxy. Gregory of Nyssa responded to Eunomius that, while the Son is not a product of will, the Father doesn’t beget involuntarily . Agamben’s claim that being’s movement is not “by nature” but by energeia also misses the Cappadocian point, which is to describe define nature precise in terms of energy and dynamism. This wouldn’t make Agamben happy, since he much prefers existence to movement, being to operativity. But Agamben’s treatment does highlight the transformation that Christianity brought to classical metaphysics.