Reason and Revelation: Why Christians Need Philosophy

You can’t call them opportunists. Starting just before the Supreme Court heard arguments calling them bigots—and ever since the Court’s DOMA ruling turned that libel into law—religious conservatives have been busy arguing about the worth of their own arguments.

Many, in particular, have questioned the value of rational defenses of marriage, and, indeed, all moral philosophy. A recent post by Joe Carter is the latest in a long (ecumenical) series, including contributions by Al Mohler, Alan Jacobs, Peter Leithart, Michael Potemra, Greg Forster, Samuel Goldman, Thaddeus Kozinski, and Rod Dreher. Most prominent are interventions by David Bentley Hart and by Jody Bottum.

Their concerns divide into three.

Some ask, first, whether moral philosophizing (including natural-law reasoning) can have autonomy from religion. Does it add anything to revelation? Can philosophy give us good answers without borrowing all its premises, and appeal, from theology?

Second, some question the social value of philosophy, especially of natural-law arguments for traditional morals. Isn’t it a waste to churn our analytical gears in careful disputation while pride parades march on and Modern Family enters a new season? Rather than argue earnestly across an impassable divide, shouldn’t we be content to diagnose it from above like good social critics?

Finally, some wonder especially about the rational case for marriage. They fear that it requires a view of reality too “enchanted” for modern ears—a moral system of objective human goods and ends, not just feelings, consequences, and consent. They fear that such argumentation requires a broader but long-lost intellectual tradition; that the battle for marriage as a conjugal union is therefore already lost; and that waging it is too far from the Church’s proper mission anyway.

A Response

In What Is Marriage? Man and Woman: A Defense, I argue, together with Ryan T. Anderson and Robert P. George, that marriage is a conjugal union of man and woman and that civil law should reflect this truth. Elsewhere we explain the importance of this fight and how and why it can be won.

Here, I will defend the idea of rationally defending marriage at all. Others have disposed quite well of the more theoretical side of recent objections to this effort. I will address doubts about its value. Since these doubts raise questions about my work with Anderson and George, I should note that both have asked me to indicate their agreement with this defense, which I will lay out in a series of three articles.

First, in today’s article, I hope to show Christian critics that Christianity itself relies on a natural-law account of marriage (and much else). In fact, some parts of Christian revelation would make no sense to people ignorant of what marriage really is; for revelation to be effective, a rational account of marriage must be possible. In this first article, then, I will take for granted basic Christian claims to show Christian critics that moral philosophy must have this much autonomy from theology: it can produce sound answers without pilfering its premises, or its plausibility, from revelation.

But even beyond the Church, as I will show tomorrow, philosophy is crucial for lives well-lived—personally and communally. Though philosophy rarely converts immediately, and never converts en masse, it is indispensable for thriving individuals and societies.

Finally, in a third article, I will answer those who accept these general points but see special problems for a natural-law defense of marriage and conclude by recalling why the fight for marriage is worth waging.

Developing Theology

In what ways do Christians rely on philosophy?

Revelation is inevitably and continuously thought out by being received and handed on. That is why the Church herself needs moral reasoning. Revelation certainly sheds light on moral reasoning, but there are also theological reasons to appeal to natural reason—and to think that it has its own axioms and appeal prior to revelation.

Note first that reason helps us to draw out the deposit of faith. The moral commandments of the Abrahamic faiths were addressed to a particular people, framed in concrete terms. It can take philosophical reasoning to work out their scope.

The Mosaic tablets forbid false witness against your neighbor; sound natural-law thinking rules out all false assertion. It is such moral thinking that gets us from “thou shalt not kill” to the splendid refinement of Just War Theory; from the Sermon on the Mount and the Parable of the Good Samaritan to Rerum novarum, Centesimus annus, and Caritas in veritate.

And only such rational development can help us achieve a second goal: applying moral theology to new circumstances. We are commanded not to kill, but only good moral thinking can show us that this norm protects human embryos and those with disabilities as well as healthy adults (but not, say, other primates). We are commanded to be fruitful and to love our neighbor as ourselves. Yet only good moral reasoning can tell us that the manufacture of children in vitro mocks the first of these commandments by flouting the principle of equality inherent in the second.

A Christian skeptical of philosophy’s value might here object that my examples only prove his point: each involves reasoning from revelation. Without an anchor in the faith, isn’t philosophy at sea? Don’t these examples show that we need “prior supernatural convictions” to drive philosophical conclusions—that there are no “purely ‘natural’ grounds” for moral principles?

This objection misses a subtle point. Philosophy does not just fill gaps in our understanding of faith without ever touching down to its own philosophical foundations. No, to apply a commandment to new cases, we need to know its rationale. On that, revelation might be silent. And then we will require bedrock appeal to reason.

Jesus made such appeals. About the scope of the Leviticus command to love one’s neighbor as oneself, a lawyer once asked Him, “Who is my neighbor?” Jesus’s reply appealed beyond the Pentateuch to natural moral sense: “Which of these three do you think was a neighbor to the man who fell into the hands of robbers?” The lawyer could answer because he knew, by reason, that we can have duties to any person. The Parable of the Good Samaritan was, among more glorious things, a philosophical thought-experiment—clarifying moral truths by basic appeal to reason.

Likewise, for a casuistry of, say, homicide, we need to know why killing is wrong when it is. And it is philosophy, not just revelation, that will show us the relevance of lethal intentions, or of fairness in accepting collateral damage. We therefore need reasoning that is philosophical all the way down, to keep faithful to moral theology.

Defending Theology

Properly philosophical reasoning also helps the Church to spread her teachings by defending them as wise counsel, not arbitrary constraint: a fruit of divine love and not despotism.

Does the Genesis concept of one-flesh union capture a real human good achievable only by a man and a woman, or is it gerrymandered to exclude the loves of a hapless few? Appealing to Genesis itself won’t defend against this challenge; natural moral reasoning can.

In fact, natural-law defenses of the Church’s moral teachings sometimes lead people to accept its authority wholesale. Seeing the Church tell the truth about morality, in and out of season, they wonder whether it is, after all, a truth-telling thing, carrying a message not its own. A prominent recent example (one of many I know) is the conversion of political philosopher Hadley Arkes, whose journey to Rome with Peter and Paul began in Athens with Plato and Aristotle.

Developing and Defending the Ethics of Marriage

If philosophy helps us to defend and extend moral-theological teaching, the current controversy over marriage is no exception.

On marriage, what revelation gives is the outline. Scripture says that maleness and femaleness are critical to how humans bear fruit and achieve order (Gen. 1:26-28); that marriage makes of man and woman one flesh (Gen. 2:24); that this bond in its fullness is permanent and exclusive by nature (“from the beginning”) (Mk. 10:5-12); and that it can’t exist between two men or two women. Some nineteen centuries of teaching yield more pointed doctrines against premarital, non-coital, and contracepted sex, but not against marital sex made infertile by chance, illness, or age.

Can we defend and develop this as anything but an arbitrary bundle of principles? Are these links between men and women, marriage and social order (or bodily union, or family life, or total commitment) morally meaningless—to be broken once we have the tools? Do some tools unknown to the Apostles—such as the anovulent birth-control pill—really break these links at all?

These questions will lead us to philosophical ones—which revelation itself tells us we can answer by reason (Rom. 2:15). Is the human good of marriage just an intense emotional bond—of which “one flesh” is only a metaphor, on which complementarity and commitment are just Hebrew cultural accretions, and openness to procreation and family a matter of taste?

Or is marriage a comprehensive union—in which man and woman become one much as the parts of a single body do (by coordination toward a bodily end of the whole)? In which the act that makes marital love is also the kind of act that makes new life? A bond that is therefore naturally fulfilled by procreation, family, and the wide sharing of home life? In which totality of union (body and mind, all domestic life) demands total commitment (permanent, exclusive)?

Natural moral reasoning can help us answer these questions—can help us defend, develop, and apply to new cases, the tersely potent sayings of the prophets, Paul, and Christ.

Making Sense of Revelation

Another point proves still more clearly that a rational account of marriage must be possible and needs to be developed.

Revelation relies on marriage as an image to convey certain truths. But for those truths to get across, people must have a sense of what marriage is prior to revelation. So Christians can infer, from the Scriptures’ vast reliance on marriage, that God expects us to know its basic structure and meaning by reason, even prior to faith.

By the same token, how we see the natural good of marriage must shape our vision of the divine goods it mirrors. For Christians, then, moral philosophizing about marriage can serve yet another purpose: giving deeper insight into revealed truths.

Thus, we know by reason that marriage is an exchange not just of goods and services but whole persons. And that is why it can mirror God’s covenant with his people: aware of the evil of a divided heart, we know what it means for God to call Israel’s impiety “fornication” and her idolatry “adultery.” Understanding that conjugal love is naturally jealous and permanent, we rejoice when Paul reveals that we are bound “in marriage to one husband … Christ” (2 Cor. 11:2).

We see that vows unite spouses in heart and mind, and consummation unites them bodily. And that is how the Gospel’s nuptial imagery can teach us the extent of our union with Christ: baptismal vows unite our hearts and minds to His, and the Eucharist unites us bodily.

Consummation embodies commitment, so it is (as Paul says) profane to seek it without being married and faithful to one’s spouse. And so, if communion embodies commitment to Christ, it must (as Paul also says) be profane to receive it without being baptized and faithful to our Lord (1 Cor. 11:27). Our natural knowledge of the first helps us grasp the supernatural truth of the second.

Finally, in the experience of marital covenant as a total sharing of selves, a man comes to see his wife’s good and his own as one: to serve one is to serve the other. Likewise for the woman. And this helps them both see what it could mean for the New Covenant so to integrate us with Christ, that whatever we do—for ourselves or others—we can do also for Him. The natural experience of total union in marriage, by which one spouse’s good is the other’s, helps us grasp and follow Paul’s command to do all things, whether for ourselves or others, “as unto the Lord” (Col. 3:23, 1 Cor. 10:31); and to see that what we do to the least of these, we do to Him (Mt. 25:40).

In these ways, revelation relies on marriage, of which we naturally know something, to tell us about the supernatural, of which we know less. It doesn’t displace but presupposes our natural moral knowledge. But it is a reflection on experience—philosophy—that builds this natural knowledge. That is why the Apostle to the Gentiles, preaching a resurrection unprovable by philosophy, still saw fit to “reason” in the “marketplace” with Stoics and Epicureans (Acts 17).

This explains why natural-law philosophy matters for the life of the Church. In tomorrow’s essay I discuss what else we can—and can’t—expect it to do, for our culture and our own lives.