I want to emphasize this at the outset because I know that what I intend to talk about has consistently proved to be the most volatile topic in Christian theology. In the history of the faith, no debates have been more contentious or more catastrophically consequential than those concerning Christology. Christian culture has never, it is true, known a moment of complete doctrinal accord, except perhaps at a point so early in its development that the very terms "doctrine" and even perhaps "Christian" are probably anachronisms. But, among all the issues that down the centuries have divided believers and afforded them opportunities for despising one another--at least, those especially adamant regarding how we should formulate the unutterable or express the ineffable or define the incomprehensible--none has resulted in greater institutional fragmentation, political disarray, and religious dissension than has that of the unity of all things in Christ. And the mischief continues down to this very day. No modern theologian, be he or she ever so revered or loved, can write a book on Christology without rousing consternation even among peers, disciples, and allies, all of whom will find something in its pages to be too low or too high, too mythical or too historicizing, or--if the complaints fall along dubious but traditional lines of dogmatic categorization--too "Monophysite" or too "Nestorian," too Lutheran or too Reformed, and so forth. It is impossible to please everyone and probably impossible to satisfy anyone. And yet we all tend to think we know what we all more or less believe on these matters.

After all, the majority of believers have the seemingly limpid formulations of Chalcedon to guide them, and those certainly appear to provide some kind of exhaustive account of the (so to speak) structure of the incarnation; and so we naturally presume that the understanding each of us has of Chalcedon--or, at least, of the terms common to both the Chalcedonian and non-Chalcedonian branches of the Great Church tradition--is the one shared by everyone else. How happy that state of idyllic innocence is, so long as it lasts--which it does right up until some barbarian is so indiscreet as to attempt to put that understanding into words, at which point everyone else is astonished by that poor soul''s perversity and folly. I expect to fare no better than anyone else on this score, and hope to fare considerably worse than many; I even somewhat wickedly relish the opportunity to play the roles of barbarian, pervert, and fool on this occasion. But I also want to make it clear at the outset that I do not imagine that I can provide some kind of final or correct solution to the mystery of the incarnation. I want only to try to understand as best I can what it must actually mean to say that Jesus of Nazareth was in every sense a true human being and also wholly identical to the eternal Son of God, the Logos in and through whom all things subsist. The reason for the issue''s perennial volatility is not, it seems to me, difficult to find: Christology is, putatively, the attempt to say how, in the single "person" of Jesus of Nazareth, "divine nature" and "human nature" have been "united to" and "reconciled with" one another; but--and this, let me note at the very start, is the somewhat scandalous claim I want to defend in all that follows--such a project can never arrive at an entirely satisfactory conclusion not simply because the mysteries toward which it points exceed our understanding, but also because the very terms in which it has been conceived and phrased are probably inherently defective. It is rather late in the long Christian day, admittedly--very near evening, some might think--to advance such a claim as a reproach or a protest; I am certainly not advocating some great revision of the tradition''s established language regarding this most essential of its mysteries. "Two natures in one person" will and must remain the basic grammar of Christian confession; and, after all, no one in all likelihood will come up with anything better to propose.

What, however, remains open for discussion (and, inevitably, for quarreling over) is how both that duality and that unity are to be understood: whether, for example, "person" here corresponds only to the word πρσωπον or only to πστασις or to both, understood as synonyms of one another; how πστασις relates to φσις and then φσις to οσα; whether φσις means something like "an ensemble of properties" or instead indicates a more radical or a more concrete kind of identity; and so forth. Alas, I suspect that such questions are inherently unanswerable, in part because of a fundamental inadequacy in the various resolutions toward which the Christological controversies of the high patristic period increasingly forced all factions, but in part also because it is precisely the indeterminacy in these words that allows them to function as doctrinal rules of usage. Certainly, in affirming both the full divinity and the full humanity of Christ, the official formulae of Chalcedonian Christology succeed no better than do the rival formulae of the Coptic and Church of the East traditions (when, of course, those latter are viewed in the contexts of Alexandria''s or Antioch''s native philosophical terminologies). Chalcedon merely established a theological and doctrinal syntax sufficiently vacuous at once to allow yet also to frustrate any more ambitiously replete conceptual semantics. And, even then, the compromise failed; the more vigorously the vying parties strove to assign exact meanings to the words they all variously employed, the more the debates tended to generate verbal distinctions that made no conceptual differences save of the vaguest kinds, the whole process culminating in differences of a far more pernicious variety: real and permanent divisions within the body of the faith. (excerpted from chapter 1).