Wakako Hirano: Substantia and Potestas: Augustine’s Theory of Persons

Concerning the Trinitarian theology, Augustine of Hippo has been criticized for disregarding the relationship of the
three persons of God. However, researchers have recently
attempted to precisely describe his theory of the persons. This paper examines
their relationship, especially that of the Father and the Son, from the
viewpoints of substance (substantia)
and power (potestas). As some researchers have noted, Augustine gives detailed explanations of the relationship of the persons in his Tractates
on the Gospel of John. When he addresses power, he distinguishes the Son’s power from that of Christ. As to the former, he emphasises substance and power are not different regarding both the Father and the
Son, based on the immortality of the Trinity, even though the Father is a
beginning in relation to the Son. Notably, Christ’s power, which is thought to
have been accepted by Christ at the time of the Incarnation, has the power to
save many people. To bridge the divide between the power of the Son and Christ,
Augustine seems to suggest the theory of predestination by explaining that
Christ was predestined to accept the power. This is indicated by Augustine’s
interpretation of John 17:2, according to which the second person of the
Trinity has the proper works in respect to his humanity and godhead. Thus, in
this paper I attempt to make it clear that Augustine’s Trinitarian theology of
the three persons is connected with predestination, especially when considering
the proper works of each person of God.