Tritheism.
Simplicity also has a way of avoiding tritheism. As both Aquinas and Anselm explain,
just because “there are three having divinity” does not mean there are “three
Gods” (Aquinas, Summa 1a.39.3). The one divine essence is not multiplied
three times: that is triplicity (Aquinas, Summa 1q.31.1;
Turretin, Institutes, 255). Triplicity leads to tritheism, because “If
God is composed of three things, either there is no simple substance, or there
is another substance that surpasses the substance of God in something” (Anselm,
On the Incarnation of the Word 4). Three things, three parts, would
compromise the one, simple essence of God (Gill, Body of Divinity, 128).
However, triplicity is not
the same thing as Trinity. Triplicity divides the essence of God by
making each person an individual agent. But the Great Tradition avoids this
pitfall by stressing that the one, simple essence has three modes of
subsistence. Rather than merely saying God is three persons, we can be more
specific: the one, undivided essence wholly subsists in three persons, each
person a subsistence of the same, simple essence. Listen to what John Gill
says: “There is but oe divine essence, undivided, and common to Father, Son,
and Spirit, and in this sense but one God; since there is but one essence, though
there are different modes of subsisting in it which are called persons; and
these possess the whole essence undivided” (Gill, Body of Divinity,
128). While simplicity precludes parts, it does not preclude eternal relations
or personal properties. For these relations do not undermine the oneness of
God, but undergird such unity.
How so?
The eternal relations of origin—the
Father unbegotten, the Son begotten, the Spirit spirited—not only distinguish
the persons, but these relations also guarantee the persons are subsistences of
the same divine essence. The divine essence is communicated from the
Father to the Son and from the Father and the Son to the Spirit. For example,
consider eternal generation. The Son is begotten from the Father’s essence, or
as the church fathers so often said, from the Father’s ousia. Later theologians
picked up on this point too. Francis Turretin wrote, “By generation the divine
essence is communicated to the begotten, not that it may exist, but subsist” (Turretin,
Institutes, 301). So, whenever we stress the relations to that which
alone is distinguish the persons, we must not forget these same relations
preserve the simplicity of the essence. (Matthew Barrett, Simply Trinity:
The Unmanipulated Father, Son, and Spirit [Grand Rapids, Mich.: Baker
Books, 2021], 146, 148, italics in original)
Social trinitarianism.
If simplicity guards against tritheism, then so too does it protect us from
social trinitarianism. If God is one in essence, then he is without a
doubt in will. “The Father, Son, and Spirit,” says John Owen, “have not
distinct wills. They are one God, and God’s will is one, as being an essential
property of his nature” (Owen, Works 19:87 [cf. 9:87-88; 12:497]). This
is essential to orthodox trinitarianism, a key pillar that protects the Trinity
from heresy as well as Trinity drift.
However, many forms of social
trinitarianism reject this belief and instead teach that there are three
centers of consciousness and therefore three wills in the Godhead. Social
trinitarianism places emphasis on the persons as a community, as a society,
each person having his own will that is not only distinct but different from
the wills of the other persons . . . This is a mistake of colossal proportions.
Despite protests to the contrary, social trinitarianism has all the ingredients
of tritheism. For where there are three wills there are three separate centers of
consciousness, and where there are three separate centers of consciousness
there are three separate gods. In this view, God no longer acts as one
because he is one (inseparable operations), but he acts as one because the three wills of the three persons merely cooperate with one another. . . .
only one will can explain how the external works of our triune God remains
indivisible. . . . “God is one,
therefore the power and operation of all the Persons are one and undivided; and
each Person is the immediate and perfect cause of the whole work” (Witsius, Exercitationes,
6.2, quoted in Muller, PRRD, 4:258).
To conclude, true unity is not a
mere unity of will(s) (this is what the Arians argued), but there must
be a unity in being (the Great Tradition) (E.g., Basil of Caesarea, Against
Eunomius, 2.14). The persons act as one because they are one—one in essence
and therefore one in will. “for there is one essence, one goodness, one power,
one will, one energy, one authority, one and the same. I repeat, not three
resembling each other,” says John of Damascus. “But the three subsistences have
one and the same movement. For each one of them is related closely to the other
as to itself: that is to say that the Father, the Son, and the Holy Spirit are
one in all respects, save those of not being begotten, of birth and of
procession” (John of Damascus, Exposition of the Orthodox Faith 8 [NPNF2
9:10]).
What, then, distinguishes the
persons if not different wills? . . . the persons are identical in all things
except their eternal relations of origin (personal properties): paternity,
filiation, spiration. These and these alone distinguish the persons. Anything
more, anything ese, and the unity of our triuine God is divided; divine
simplicity is compromised. God is no longer simply Trinity.
(Ibid., 149-50, emphasis in italics in original, emphasis in bold added)
