Social trinitarianism has been on its heels in recent years, but in a bracing article in IJST, Gijsbert van den Brink of the Free University of Amsterdam thinks it can respond to the varied criticisms. It needs to be chastened and modified at points, but for van den Brink social Trinitarianism has not been refuted.
The objections are various: questions about the usefulness of social trinitarian theology, historical questions about the relation of social Trinitarianism to patristic theology, the purported biblical roots of social Trinitarianism, social Trinitarian claims about the being of God, and questions about whether social Trinitarians can do justice to the unity of God, and avoid falling into tritheism (337).
On the historical question, van den Brink refers to the recent work of Michel Rene Barnes on the influence of de Regnon’s East-West split in Trinitarian theology. He acknowledges that patristic theology is more complicated than some social Trinitarians have claimed, but van den Brink suggests that “contemporary social trinitarians still can turn to the Cappadocians for drawing inspiration from their work, expanding not only on their well-known use of social metaphors but also on their distinctive definitions of ousia and hypostasis” (340-1). He cites Jenson’s comment that the criticism of the critique of Augustine often amounts to pointing out good things in Augustine. Social Trinitarians can concede that Augustine was profoundly Trinitarian in many ways, and yet criticize certain of Augustine’s decisions.
He addresses Carl Mosser’s argument that social Trinitarianism “turns talk about the distinct roles of Father, Son and Spirit in the New Testament narratives into ‘direct descriptions of their immanent relations,’” and runs the risk of “collapsing ‘the distinction between the economy of salvation narrated by the text and the life of God in himself’” (344). But van den Brink rightly responds by pointing out that limiting the biblical descriptions to the economic level leaves us “agnostic about who God is in Godself” and makes it likely that we will project “our own ideas and intuitions” onto God (345).The whole point of the social Trinitarian project, he points out, was to ensure that God is knowable. If the Deus revelatus and the Deus in se do not correspond, “we will never know whether the God who is revealed to us is the true God, or whether the true God is totally different” (346).
Van den Brink ends his essay with a couple of positive arguments in favor of social Trintarianism, The first is based on three premises: First, “a person who reads the New Testament would naturally develop a social account of the economic Trinity”; second, “when we have to do with God’s revelation . . . we have to do with God”; third, “the economic Trinity is the immanent Trinity” (349). On this basis, the economic depiction of interaction among Persons, especially among Father and Son, is a revelation of God’s own inner life, and this suggests that “a social (or relational) account of the Trinity may provide the most compelling interpretation of the biblical saying that ‘God is love’” (349).
His second argument starts from soteriology. If, as many have argued of late, “we need a participation-oriented account of salvation in order to do justice to the heart of the gospel, it seems that we need a relational model of the Trinity for that very same reason: the deeply personal union and communion with God and with our fellow-humans to which we are restored by grace is not something alien to God, but a reflection and extension of God’s own life-in-communion” (350).
Van den Brink’s article hardly settles the debate. But it shows that there is life in social Trinitarianism yet.
(Gijsbert van den Brink, “Social Trinitarianism: A Discussion of Some Recent Theological Criticism,” International Journal of Systematic Theology 16  331-350.)