Serious thought about what there is and what it’s like leads in the end to one of two conclusions: Christ or nothing. Christ-centered trinitarianism sees Jesus, the incarnate Lord, as the crux of the cosmos, and the cosmos as a series of intensities brought into being out of nothing and ordered according to degree of intimacy with the triune Lord. Evil, in this view, is secondary: a privation, a destructive loss of intimacy. Nihilism asserts the primacy of emptiness over plenitude, absence over presence, death over life, and, therefore, the secondary and finally illusory nature of what appears. Evil, in this view, is on a par with everything else, as real as anything else, one more discordance in an already inharmonious field.

Deciding for trinitarianism over nihilism is not like deciding for theism over atheism. That debate, especially in its currently popular forms (Christopher Hitchens, Daniel Dennett, Richard Dawkins), is about whether the furniture of the cosmos includes an item called “God.” Arguments of that sort have almost nothing to do with the triune God of Abraham and Isaac and Jesus. Better to think about whether the cosmos is plenitude’s overflow—its end light everlasting—or whether it is instead like the green and ghastly light-show produced on the inner eyeball by a detaching retina, a show whose end is blindness. This is a much more interesting debate, though also a much more difficult one—difficult because it is the only finally important debate and also because its very terms mean that it cannot be resolved by argument alone. It is often a debate not only about what is the case, but also about how to construe Christianity.

The Monstrosity of Christ is the record of a debate about exactly these matters. Its editor, Creston Davis, bills it as the literary trace of an intellectual smackdown: two virtuoso heavyweights engaging in “ultimate fighting” over how Christianity should be construed. There’s no clear victor: there’s no actual blood on the floor, and both men live to write another day. Their debate is nevertheless entertaining, witty, and learned, though not an easy read unless you’re already deeply familiar with the work of one or both of the protagonists, as well as with Hegel, Heidegger, Lacan, Derrida, Chesterton, Aquinas, Levinas, Badiou, Agamben, and others—a litany of names not quite as long as that of the saints and martyrs, but long enough.

So who are the protagonists in this cage match?

John Milbank is an Englishman and an Anglican with increasingly Catholic sympathies, the founder and éminence grise of the “radical orthodoxy” movement, which is now a little more than a decade old. The principal goal of that movement has been to show that every academic discipline and indeed every intellectual act is, whether it knows it or not, at theology’s service, and to do so by re-reading the whole of Western intellectual history through the lens of an Augustinian Platonism. Radical orthodoxy’s slogan might well be Bonaventure’s omnes cognitiones theologiae famulantur (“every act of cognition is theology’s slave”). Its foundational texts are Milbank’s Theology and Social Theory (1991), and Catherine Pickstock’s After Writing (1997).

Slavoj Žižek was born in Ljubjlana, then in Yugoslavia, now in Slovenia, and trained as a philosopher there and in Paris. He was a member of the Communist Party until 1988, and he remains a Marxist. He has taken to saying things like “communism will win” (in a 2008 interview) with a greater and greater frequency as the prospect seems less and less likely. That is a sign of his intellectual temperament, and it is no accident that among his many recent books is one called In Defense of Lost Causes (2008). Žižek is not, by his own account, Christian. But since the late 1990s, his work has shown increasing interest in Christian thinkers (Chesterton and St. Paul figure largely) as a resource for overcoming liberalism’s tendency to privatize ethics and reduce politics to pragmatics. What Žižek wants is a materialist fundamentalism, by which he means a view that reconnects the unconditional demand for a life rightly lived to a radical politics.

Milbank and Žižek differ about much, clearly. But they also share much. They are of the same generation (Žižek was born in 1949 and Milbank in 1952); they have read and endlessly written about the same books (Hegel is a pivotal figure for both); they are joined in deep dislike of—and a desire to subvert—global capitalism and its kissing cousin, political liberalism, as well as its conceptual acolytes, the defenders of “the postmodern free play of endless difference.” They both favor the Hegelian word-flood as a means of persuasion (austere Wittgensteinean brevity is not for them); and they both affirm Christ’s “monstrosity,” by which they mean, following that word’s etymology, that he is a disfigured prodigy whose exceptionality transfigures everything else. What they differ about is the significance of dialectics, paradox, and God.

Žižek is an advocate of the dialectic in its deep-Hegelian and fully materialist sense. According to this understanding as applied to the Trinity, the first dialectical move is God the Father’s showing of himself in creation, an act in which the fundamentally miraculous appears commonplace; the second is the begetting of the incarnate Son, in which that ordinariness is monstrously (prodigiously) disfigured and thus transfigured by way of a death; and the third is the sending of the Spirit in which everything returns to normal, but with the death remaining at the dialectic’s crux. That, for Žižek, is the work of the Trinity—the Trinity at work, economically, as theologians like to put it—and outside it there is nothing. The Father shows himself without remainder in creation, the Son dies without Resurrection on the Cross, and the Spirit’s activity in the world exhausts the meaning of the Resurrection: it is what the Resurrection is. To live as a Christian, then, is to live as an individual in a community of believers that is itself, now, what and where God is. For Žižek, “God” is not and cannot be above, or extrinsic to, alienation; he does not stand impassive before a soon-to-be-resolved suffering on the Cross. Rather, the alienation of the Cross, with its cry of dereliction, belongs to the very heart of God and shows him to us as he is: dying and dead.

That is grimly bracing. It yields a materialist world of individuals whose ethic is “doing what is to be done in a weird coincidence of blind spontaneity and reflexive distance, helping others while avoiding their disgusting proximity.” It is a world with hard edges, and without sentiment, in which Christian talk provides the most precise available language for the dialectic, but only so long as the immanent Trinity (the Lord as he is in himself) is entirely subsumed into the economic Trinity (the Lord as he works in the world). Anything else is both insufficiently dialectical and insufficiently Christian.

Milbank disagrees. For him, Žižek’s dialectical version of Christianity is gnostically Protestant, and he opposes to it a “radically Catholic” version of Christianity which “sustains genuine transcendence only because of its commitment to incarnational paradox.” This idea of paradox is at the heart of Milbank’s Christianity. By this word he means not only a judgment or event against expectation and therefore hard to understand (as the word’s ordinary etymology would suggest), but also one overflowing with glory (playing on the double meaning of doxa, as both “glory” and “opinion” or “judgment”). Christ is in this sense paradox, and most especially in the crucifixion and Resurrection. The radicality of Žižek’s dialectic is then countered with a metaphysic of participation and a doctrine of analogy. Created beings are all, according to their kind, participants in the Lord; and to speak of them is to speak, analogically, of the Lord. This is an Augustinian-Thomist view. (Milbank is right to point out that it also Platonist.) Taken seriously, it precludes the possibility of thinking of being and its negation, nothingness, in purely abstract terms, and it is only in abstract terms that being and nothingness are both contentless and therefore indistinguishable from each other. Milbank accuses Hegel and Žižek of thinking and speaking of being (God) and beings (his creatures) univocally, as though they could be set against one another on a level playing field. This conceptual move is the result, he says, of having forgotten the fundamental analogical-participatory grammar of Christianity, and such forgetfulness leads to nihilism—if it isn’t nihilism already. Hegel did not refute or transcend this analogical understanding of Christianity. He never understood it in the first place.

Where Žižek identifies the economic Trinity with the immanent Trinity (once you have accounted for God at work in the world, you have finished accounting for God), Milbank keeps the two aspects of the Trinity in tension. That the world is at all, and that it is as it is, can be understood only by asserting the participation of the economic in the immanent. This difference goes deep. Žižek’s understanding of the cosmos is essentially about conflict. The dialectic proceeds by erasure; God really and finally dies on the Cross. Milbank’s vision is one of perpetual peace. His ethic commends action that participates in this peace by attending nonviolently to the beautiful particularity of each being. Milbank cannot say, as Žižek does, that the proximity of beings is disgusting. For him, it can only be beautiful.

There is great intellectual energy in this book. Both of its contributors have read and thought voraciously, and want to let you, the reader, know that. Too often, however, this leads to bedazzlement rather than enlightenment—are they arguing about what Hegel really meant or about the truth of things? Why do we need thirty pages of disagreement about the interpretation of Eckhart? Do we really need a five-page excursus on Diane Setterfield’s 2006 novel The Thirteenth Tale (Milbank), or one on Terry Eagleton’s (mis)understanding of Heinrich von Kleist’s novella Michael Kohlhaas (Žižek)? These things are there not because they are required for the argument, nor even because they are entertaining (though they often are)—they are there because both these men have an intellectual temperament that requires them to consume the world of the text and to let you, the reader, see them chew its cud. The spectacle is often edifying, sometimes funny. It is also sometimes repetitious or puzzling.

The best thing about this book, and about much else in the work of both its authors, is that Christianity emerges as the deep grammar of the world, and the construal of that grammar emerges as a task more important than any other we face. Milbank and Žižek disagree about how it should be construed, but they agree about the importance of the task, and their agreement shows the narrow shallowness of much that passes for theology—and, especially, of much that passes for debate about God’s nature and existence.