Is Peter Leithart also among the Nominalists?

Here's a teaser from my latest article with the Colson Center 'Gay Marriage and Creational Realism,' in which I interacted with the implicit nominalism of Peter Leithart's approach to the marriage debate. The entire article can be read here.

The impasse of communication that persists in the “gay marriage” debate has left some Christian thinkers suspecting that genuine dialogue with unbelievers about the meaning of marriage is impossible. The thinking tends to run something like this: if someone doesn’t share our Christian worldview, there isn’t much we can appeal to when defending traditional marriage. Moreover, why would it even make sense for the other side to listen to us given that they don’t share the worldview that gives rise to our understanding of marriage in the first place?

Peter Leithart reflected this attitude in his post earlier this year, “Gay Marriage and Christian Imagination.” Musing on a debate that took place between Douglas Wilson and Andrew Sullivan, Leithart suggested that we need “a cultural revolution” before our arguments for traditional marriage can even to be heard. This is because appealing to “liberal polity…leaves biblically-grounded Christians with little to say.” All we can do is fall back on “The Bible says” and make “theologically rich, biblically founded arguments against gay marriage” that will probably not “make any sense to the public at large” but may have an aesthetic pull.

Although numerous thinkers, including myself, have shown that it is possible for Christian to make non-religious arguments to show how gay marriage is a public threat (see here and here and here), Leithart concedes that “it’s a hard case to make” that “gay marriage has harmed society.” In the end, Leithart wonders if we are trapped in our own interpretive communities, unable to truly communicate with those outside: “Perhaps we have entered a phase in which God has closed ears, so that whatever we say sounds like so much gibberish….Because the only arguments we have are theological ones, and only people whose imaginations are formed by Scripture will find them cogent.”

The problem here is that Leithart’s approach only works if one begins by divorcing what we know of marriage from the order inherent in creation. If the Christian understanding of marriage arises from the raw command of an omnipotent God arbitrarily constituting the world in a certain way that might just of easily have been otherwise, then I agree that there is little we can say about the moral constitution of the world to those who do not share our theocentric worldview. On the other hand, if we are realists then we believe that God’s commands about sexual ethics flow out of the teleological directedness intrinsic to creation itself (a point I have developed in more detail in my article ‘Sex and the Ockhamist Revolution.’) Under the realist scheme of things, it becomes possible to appeal to unbelievers on the basis of that ordering without needing to invoke explicitly Biblical arguments.

This is exactly the line that Girgis, Anderson, and George have taken in their book What is Marriage? These authors have received push-back from the Christian community for being content to construct purely secular and even non-moral arguments. However, the irony is that we actually have good Biblical reasons for making non-biblical arguments. It is clear from Genesis that believers and unbelievers alike share a common world, a common rationality, and a common human nature. This remains constant even if an unbeliever’s worldview prevents him from giving a consistent account of these things, just as gravity remains constant even for those whose worldview cannot give a coherent explanation for gravitation.
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Christians generally understand this principle in other areas. For example, in mathematics we generally understand that even if the worldview of an unbeliever precludes him from being able to give a consistent account of mathematics, a Christian mathematician can still prove mathematical truths to the unbeliever on the basis of a shared creation without having to explicitly invoke the Bible. Now a Christian mathematician may want to invoke Scripture for evangelistic purposes, or he may want to use reason to demonstrate that an atheistic worldview cannot consistently explain mathematics, but this is not strictly necessary before a believer and unbeliever can communicate meaningfully about numbers.
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Similarly, in talking about the meaning of marriage it is possible to appeal to the realities of our shared creation without needing to invoke the Bible. We can point to the order of the world and the pushback that occurs when that order is flouted. We can show that biologically, socially, psychologically, legally, and historically, there are good reasons to be cautious about gay marriage, and we can make these points by appealing to creation itself. This is because unbelievers live in a world informed by moral truth just as they live in a world informed by scientific and numerical truth. When confronted with unbelievers who deny this fact and attempt to live as moral relativists, we should not shrink back from pointing to the many ways that our shared experiences in the world contradict moral relativism.
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The Christian nominalist is not in the same position of being able to appeal to creation. This is because, for him, there can never be any question of a right-ordered nature that stands antecedent to, and the reason for, God’s commands: we simply need to know what the rules are and to keep them. All the ordering in our world becomes deliberate ordering, and creation becomes radically contingent. But this brings communication into atrophy, for then we can never make appeals to creation, and if someone with a different worldview disagrees with our morality, all we can do is to throw up our hands and say “Unless you accept the Bible, we really don’t have any basis to talk about this.”
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(We see this same nominalist bent in numerous other areas, where Christian reluctance to appeal to the patterns of creation throws many upon the type of narrow Biblicism that erroneously equates any appeal to creation as either a concession to secular epistemology or an abandonment of Scripture’s sufficiency. This error surfaces in theonomy, in certain forms of presuppositionalist apologetics, in nouthetic counselling, in Christian rejections of natural law theory, and in various modalities of Biblical worldviewism when applied to the liberal arts. Such ideas often begin by turning away from a rationality grounded in the patterns of creation and, consequently, seeking to interpret the Bible in a void. The end-result is often the type of bastardized and non-historical approach to Sola Scriptura similar to what T.M. Moore addressed in his article, “Worldview: Biblical or Christian.”)