Natural lawyers commonly cite a passage from the second chapter of Paul’s letter to the Romans to show the existence of natural law to Christians. While I accept some version of natural law, natural lawyers often seem to want to derive much more from the text than it supports.

The commonly quoted passage from the book of Romans is this:

For when Gentiles who do not have the Law do instinctively the things of the Law, these, not having the Law, are a law to themselves, in that they show the work of the Law written in their hearts, their conscience bearing witness and their thoughts alternately accusing or else defending them . . .

The place of this text in Paul’s broader argument helps us understand the argument he makes here, and we’ll consider that below. But even the text as often quoted has problems when deployed as a reference for the idea of a broadly accessible morality discerned in nature.

One word in the passage that seems to drop out when commentators quote or cite it as support for natural law is the word “when” at the very beginning of the sentence. “For when Gentiles . . . do instinctively the things of the law . . . [they] show the work of the Law written in their hearts.”

The “when” would suggest the possibility of significant limits on the extent to which natural law is written on people’s hearts. Consider a similarly phrased observation: “When my son visits his grandmother, he shows himself helpful.”

This statement says nothing about my son’s helpfulness at places other than his grandmother’s, let alone that he’s generally helpful. It’s a statement about a condition that holds when my son is helpful. Indeed, the sentence could be used to discuss how typically unhelpful my son is in every other place than his grandmother’s.

Paul’s argument in this text could be consistent with what I call “Swiss-cheese” morality. There could be lots of holes in a person’s natural morality—huge air pockets of amoralism—yet Paul’s statement would still hold true for that person. That Gentiles show the work of the law when they instinctively do the things of the law does not say anything about how commonly the condition holds.

Paul’s broader argument, after all, is about guilt rather than morality. Natural lawyers often cite the passage with the suggestion that the guilt about which Paul writes in this passage necessarily assumes a law that causes that guilt. And so it does. Yet this guilt does not predicate a broad swath of common morality accessible by reason.

Indeed, Paul’s claim would hold true even if a person’s instincts witnessed to only one moral obligation that the person transgressed during an entire lifetime. Recall that with the breaking a single commandment one becomes guilty of breaking the entire law. That may seem an extreme case, yet, on an individual level, I know that I have had a guilty conscience about far fewer sins than I have committed.

The air pockets in the Swiss-cheese of natural law could locate around substantive requirements of morality—one could take a life without a twang on conscience, or commit adultery, or thieve another person’s goods. But the air pockets might also result from false limits on the extent of the moral obligations to others, perhaps holding that obligations to right behavior do not extend beyond immediate family or clan, or beyond showing honor to other thieves.

Indeed, even some people who exposit the natural law could be affected by the fall, failing to identify obligations that the law requires, or affirming obligations that the law does not impose. Christians, too, have on more than one occasion accommodated the spirit of the times, thereby conforming their morality to that spirit rather than to the Spirit.

Beyond the possible Swiss cheesiness of the moral instincts discussed in this text, natural lawyers also often overlook the temporal expectations in the passage, an expectation that suggests the conscience of the Gentile witnesses at a specific point in the future rather than it being a transhistorical experience. Consider the passage quoted somewhat more broadly:

For all who have sinned without the Law will also perish without the Law, and all who have sinned under the Law will be judged by the Law; for it is not the hearers of the Law who are just before God, but the doers of the Law will be justified. For when Gentiles who do not have the Law do instinctively the things of the Law, these, not having the Law, are a law to themselves, in that they show the work of the Law written in their hearts, their conscience bearing witness and their thoughts alternately accusing or else defending them, on the day when, according to my gospel, God will judge the secrets of men through Christ Jesus.

The perishing without the Law that Paul refers to here is perishing on the day of judgment. So, too, the specific witness of the conscience is active on the day of judgment, “their conscience bearing witness and their thoughts alternatively accusing or else defending them, on the day when, according to my gospel, God will judge the secrets of men through Christ Jesus.”

To be sure, this does not rule out the possibility that the conscience works in the here and the now. After all, the instinctive doing of the law is in the here and the now. Yet it is Paul who distinguishes between the instinctive doing of the law today and the work of the conscience in accusing or defending on that future day.

Natural law theorists would seem to need to push the witness of the conscience from this future date into the here and now. To work as a practical matter for the foundation for a recognizably common morality accessible by Christian and non-Christian alike, however, the conscience would need to be activated naturally, or naturalistically, rather than spiritually. It is at this point that questions about how optimistic a view of human nature natural law theory requires would seem to have some bite. I’m not suggesting that the questions are insuperable, only that the Scriptures have a bit to say on the question as well.

James R. Rogers is department head and associate professor of political science at Texas A&M University. He leads the “New Man” prison ministry at the Hamilton Unit in Bryan, Texas, and serves on the Board of Directors for the Texas District of the Lutheran Church-Missouri Synod. His previous “On the Square” articles can be found here.

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