In his Modern Theology article on Maximus, David Yeago helpfully lays out the intentions and assumptions of what he calls Neo-Chalcedonian Christology. The overall aim, he says, “was to interpret the definition of Chalcedon in a manner faithful to the central christological insights of Cyril of Alexandria,” and “the main conceptual device used in doing so was the notion of hupostasis , which had developed into a fairly precise instrument through its employment in trinitarian theology, but had not previously been used with equal rigor in discussions of christology.” Neo-Chalcedonian Christology’s main achievement was the idea of “union with respect to hupostasis ,” which Yeago calls “the centerpiece of their attempt to integrate the Chalcedonian ‘two natures’ into a consistently Cyrillian insistence on the strict identity of the divine Logos with the human Jesus.”

Yeago lays out several main assumptions of this school:

First, in contrast to the Antiochene school, the incarnation was not conceived of as primarily a metaphysical puzzle about how the infinite can inhabit the finite, or how divine and human can beocme united in a single being. Yeago writes, “as Paul Wesche has pointed out in the case of the Antiochene tradition, the unity of Christ is seen as the product of the incarnation; the christological problem is taken to be that of explaining how such a metaphysically odd product could be constituted.” Neo-Chalcedonians reject this formulation of the question, following Cyril’s example. For them, “The subject-matter of christology is not ‘natures’ and their possible or actual synthesis, but rather a person, Jesus of Nazareth, who is confessed to be the Son of God. The one Jesus Christ is the datum, the presupposition, given in Scripture and the doxology of the Church; the starting-point for christology is the single ascriptive subject of the Gospel narratives and the praise of the community.” In short, “The christological problem . . . is rightly understood not as a metaphysical puzzle about how the divine and the human might be one, but as the more modest problem of explicating coherently what the Bible and the liturgy say about Jesus.”

Second, “Neo-Chalcedonian christology is not intended to offer a speculative description or explanation of the reality of the incarnate Son of God. This would make nonsense of the repeated assertions of all the ancient Greek christologians that such a description is impossible in principle. Rather, Neo-Chalcedonian christology should be read as a highly technical attempt to explicate the logic of Christian claims about Jesus of Nazareth.” As Yeago puts it, “the question animating the Neo-Chalcedonians is not . . . ‘What is the being of the incarnate Logos like?’ but rather, ‘What does it mean to say ‘the Logos became flesh’?’”

This means, third, that “the technical conceptualities of the Neo-Chalcedonian christology should be taken as open-textured, formal categories, instruments of analysis rather than heavily determined, materially weighted concepts, carriers of far-reaching substantive commitments. They are, so to speak, grammatical rather than constitutive categories, metaphysica generalis rather than metaphysica specialis , heuristic rather than explanatory in function.”

He illustrates this third point by expounding the Neo-Chalcedonian use of the hypostasis/ousia distinction. This is “at bottom a simple, commonsensical distinction, grounded in observation of the way we talk in ordinary language.” We talk at the register of ousia when we ask “what” a thing is, and speak kath’ hupostasin when we ask “who” someone is. Maximus’ use of the soul/body distinction in his discussion of Christology should be understood from this angle - not as a “model” or “explanation” of the incarnation, but as an exploration of the grammar of terms of unity and distinction.