Continuity or Discontinuity in the Christian Moral Tradition? The Magisterial Protestant Reformers on the Natural Law
J. Daryl Charles
Contemporary Protestants, who otherwise have much in dispute, share common ground in their general opposition to natural law thinking. This opposition, moreover, encompasses both revisionist and orthodox thinkers and has been with us for several generations. Across Protestantism one can find a broad consensus that rejects the natural law as a metaphysical reality through which God reveals himself to all, apart from special revelation and applying to everyone, at all times, and in all places.
Among more theologically orthodox Protestants, this opposition arises from a cluster of related—and perhaps understandable—concerns. They worry
· that natural law thinking fails to take seriously the condition of human sinfulness;
· that misguided trust is placed in the powers of human reason, which has been debilitated by the fall;
· that the ethical norms as mirrored in the OT and NT, as well as the means of fulfilling these norms, are distinct;
· that natural thinking is insufficiently Christocentric and grace-centered;
· and that natural law is therefore autonomous to the center of biblical ethics.
When not long ago, in the context of a discussion of faith and culture and moral law, I suggested to a Presbyterian (PCA) pastor the place of natural law ethics as a means to establish common ground with unbelievers, this pastor seemed blindsided, unable either to affirm the place of natural law thinking in the historic Christian tradition or to acknowledge the propriety of arguing on the basis of human nature and human design.
Happily, there are signs in more recent years that Protestants are beginning to rethink their understanding of the natural law. Perhaps the collapse of moral norms here in the West is a significant factor in this development. For me, that rethinking occurred while I was doing public-policy work in criminal justice in Washington, DC, before entering the university classroom full-time. During this season of life I was led to ask, Why does one find such vehement opposition to natural law thinking especially among very influential theologians—for example, Karl Barth, Helmut Thielicke, Paul Lehmann, Jacque Ellul, John Howard Yoder, and Stanley Hauerwas (to name but a few)? In examining the writings of the magisterial Protestant Reformers of the 16th century, I discovered that they do not share the opposition to or neglect of natural law characteristic of late-modern Protestants. Although it is true that they championed a particular understanding of grace, faith, and justification that took issue with their Roman Catholic counterparts, they maintained continuity with the wider Christian moral tradition as to the natural law and the moral revelation of the created order. The 16th-century Reformation controversies were foremost soteriological and ecclesiological, not ethical.
To the surprise of some, Luther, Calvin, and company affirmed the natural law, though it was not a major focus of their writings. Indeed, most of the magisterial reformers do not develop natural law analysis in any sort of systematic way, but simply take it for granted. One exception to that abstention from systemic development of natural law thinking is Philip Melanchthon, Martin Luther’s university colleague at Wittenberg, about whom I’ll have more to say.
Let us begin with Luther, in whose theological framework natural law thinking is firmly ensconced. In his writings Luther describes the innate awareness of right and wrong behavior in two ways. He speaks both of Naturrecht (“natural justice”) and natürliches Recht (“natural law”), and has this to say about the latter:
“Thou shalt not kill, commit adultery, steal, etc.” are not Mosaic laws only, but also the natural law [natürliches Recht] written on each man’s heart, as St. Paul teaches (Rom. 2). Also Christ himself (Matt. 7) includes all of the law and the prophets in this natural law.[2]
Referring to the awareness of the so-called “Golden Rule” in all people, Luther writes, “By nature they judge that one should do to others what one wants done to oneself.” Luther is well aware of the misperception among the religiously-minded that the natural law is the common fund of only Christian societies. To the contrary, he insists, it is demonstrated by human experience that all nations, cultures, and people-groups possess this rudimentary knowledge. The natural law, he insists, “is written in the depth of the heart and cannot be erased.”[3] It, therefore, exists as a common moral standard among non-Christian people-groups; Luther writes: “Natural law is a practical first principle in the sphere of morality; it forbids evil and commands good . . . The basis of natural law is God, who has created this light, but the basis of positive law is civil authority.”[4]
In his 1525 treatise How Christians Should Regard Moses, Luther distinguishes between the law of Moses, with its historically conditioned components and stipulations for theocratic Israel, and the natural law. “If the Ten Commandments are to be regarded as Moses’ law, then Moses came too late,” Luther quips somewhat wryly, because “Moses agrees exactly with nature” and “what Moses commands is nothing new.”[5] What’s more, Luther adds,
then Moses . . . also addressed himself to far too few people, because the Ten Commandments had spread over the whole world not only before Moses but even before Abraham and all the patriarchs. For even if a Moses had never appeared and Abraham had never been born, the Ten Commandments would have had to rule in all men from the very beginning, as they indeed did and still do.[6]
The law that stands behind the Ten Commandments, Luther notes emphatically, was in force prior to Moses, from the beginning of the world, and also among all the Gentiles. So far as the Ten Commandments are concerned, “there is no difference between Jews and Gentiles.”[7]
Luther allows little room for misunderstanding: “We will regard Moses as a teacher, but we will not regard him as our lawgiver—unless he agrees with both the New Testament and the natural law.”[8] And: “Where . . . the Mosaic law and the natural law are one, there the law remains and is not abrogated externally.” By contrast, those aspects of the Mosaic code that were temporal and confined to theocratic Israel are “null and void” and “not supported by the natural law.”[9]
In his treatise on temporal authority, Luther deliberates over particular situations that require Christians to participate intelligibly with non-Christians in the public sphere. Two such potential situations are the unlawful seizure of private property and resolving financial debts. Luther exhorts his readers to use both “the law of love” and “the natural law.” However, when charity has no observable effect, the latter is to be our guide, since natural law is that “with which all reason is filled.”[10] And where the two parties are not Christians, “then you may have them call in some other judge, and tell the obstinate one that they are acting contrary to God and natural law.”[11]
It should be emphasized that Luther is perfectly content to allow faith or revelation and the natural law to stand side by side. The natural law was presumed to be at work in all people and thus to be lodged at the core of Christian social ethics. Were this not the case, Luther reasons, one would have to teach and practice the law for a long time before it became the concern of conscience.
Philip Melanchthon, Luther’s colleague at the University of Wittenberg, is in many ways the “quiet reformer”[12]—even the “forgotten reformer,” given how he tends to be overlooked in most discussions of the magisterial reformers, disappearing in Luther’s shadow. This is most unfortunate, since Melanchthon was “the chief teacher and instructor, the scholarly publicist, and the theological diplomat” of the Lutheran Reformation.[13] He wrote the very first Protestant systematic theology, 51 editions of which were published during his lifetime. And during his lifetime, not posthumously, he had earned the reputation Praeceptor Germaniae, “The Teacher of Germany.”
Melanchthon understands natural law in much the same way as Luther. And he devoted more attention to law and moral philosophy than any other Protestant reformer. There are several reasons for this. First, such focus was part of his integrated thinking as a true “Renaissance man” devoted to the liberal arts. Second, as “the ethicist of the Protestant Reformation,”[14] he saw the need to keep theology and philosophy wed; and on this score, not Luther but Melanchthon had it right.[15] In addition, he constantly wrestled with finding a middle way between the poles of antinomianism (or law-denying, as found among the “radicals” and the Anabaptists, for example) on the one hand and works righteousness on the other. The events of the 1520s and 1530s—for example, the peasant uprisings and the radical Anabaptist experiment in the north-central German city of Münster to establish the “New Jerusalem” by force—well illustrated for Melanchthon the tragedy of a “lawless” view of Christian faith. Melanchthon worried much throughout his career about antinomian tendencies that often accompanied new outbreaks of religious enthusiasm. Melanchthon’s response, similar to that of Luther, was that both law and gospel continually need to be preached. Law is not only a necessary preamble to the gospel of Christ by awakening within human beings the reality of human fallenness, but it also furnishes the foundation for true piety and virtue, that is, the moral life.
Melanchthon joins Luther as well as Calvin in distinguishing between three types of law—ceremonial, judicial, and moral. Concerning moral law, all three reformers insist that the two former types have passed away while the latter, as the Decalogue illustrates, is abiding.[16] Melanchthon’s defense of the natural law proceeds from his reading of Romans 2:15—awareness of the natural law has been “grafted into the nature of man,” thereby mirroring the image of God.[17] His understanding of natural law is shaped by two theological premises. One is his understanding of human beings created in the image of God. Hence, humans possess “the natural knowledge of God and of the governance of our conduct”—an awareness that has been “grafted into the nature of man” as part of “the likeness of God.” A second premise is that natural law has a pedagogical role in society. That is, moral law both serves as a restraint, thereby having a civil function, and it guides, protects, and assists us in cultivating virtue; thus, it functions internally and externally. A feature unique to Melanchthon among the reformers is his development of the three purposes of natural law for civil use and criminal justice: it is retributive, deterrent, and rehabilitative in its character and function.[18]
Given the emphasis in Calvin’s theological system on divine sovereignty and human depravity, one might assume that the reformer would have a dim view of natural law, yet he acknowledges the argument of St. Paul, that the Gentiles “show the work of the law written on their hearts” (Rom. 2:15). Calvin’s description of natural law agrees with that of Luther and Melanchthon: “the very same things that are to be learned from the Two Tables [of the Ten Commandments]” are “written, even engraved, upon the hearts of all.”[19] In Calvin’s understanding, the activity and moral insights of conscience represent the mode and language by which the natural law is operative in the human person. An unchangeable “rule for the right conduct of life,” the natural law for Calvin is the “apprehension of the conscience” and thus a common law among all people.[20]
Calvin shares the Thomistic assumption that the human person is “by nature a social animal,” and because of this anthropological reality, human beings are disposed “through natural instinct to foster and preserve society.” The consequence is that “every sort of human organization must be regulated by laws,” without which there would be no civil order.[21] Since the “seeds” of just laws (his words) “have been implanted in all men,” they are unchanging despite the vicissitudes of life. Neither war nor catastrophe nor theft nor human disagreement can alter these moral intuitions since nothing can “nullify the original conception of equity” that is implanted within.[22]
We noted the element of human depravity for which Calvin is well known. How corrupt is the human heart? Thoroughly. Is there any realm that has gone untouched by human fallenness? Emphatically not. But to acknowledge the pervasiveness of our fallen nature is not to obliterate the rudimentary moral sense in each person: Calvin writes:
When men grasp the conception of things with the mind and the understanding they are said “to know” . . . In like manner, when men have an awareness of divine judgment adjoined to them as a witness which does not let them hide their sins but arraigns them as guilty before the judgment seat—this awareness is called “conscience.”[23]
This inner awareness, notes Calvin, “pursues” the person to the point of “making him acknowledge his guilt.” This, he observes, agrees with St. Paul’s teaching in Romans 2, namely that “their thoughts accuse or excuse them in God’s judgment.”[24]
Among the Swiss reformers, both the restraining as well as the directing functions of natural law are presupposed. Additionally, the threefold use of the law—ceremonial, judicial, and moral—for which the Protestant reformers are well known finds a supplemental use in the Swiss Reformational emphasis on covenant and is imported into the judicial realm. Covenant not only provides a theological basis for understanding divine work in history, but conjoined to natural law it furnishes the basis for communal and civil obligations that are thought to be binding on all people and societies.
In the thought of Huldrich Zwingli (1484–1531), the natural law serves as a bulwark and primary vehicle by which to resist injustice and political oppression. Zwingli is in agreement with other reformers that all human laws should conform to the natural law, which has been implanted in the hearts of all people, but he goes beyond Luther in asserting that the natural law is the equivalent of “true religion, . . . the knowledge, worship, and fear of the supreme deity.”[25] In contrast to the Lutheran position and in keeping with the Swiss Reformational distinctive, Zwingli believes that due to the imperfection of reason, only those rulers and magistrates who are God-fearers properly know natural law.
Heinrich Bullinger (1504–1575), perhaps best known for his role in drafting the Second Helvetic Confession of 1566, in even more pronounced ways affirmed the “law of nature” as “an instruction of the conscience, and as it were, a certain direction placed by God himself in the minds and hearts of men, to teach them what they have to do and what to eschew.”[26] Have moral norms—and thus the requirements of human societies—changed at all in the period of the New Covenant? Bullinger answers emphatically in the negative. We are still to regard basic moral truth, respect parents, live out the Golden Rule, and keep the Ten Commandments, for the natural law reminds us that there exists an objective moral order in which human laws are said to inhere. The moral law is that which teaches men right conduct and sets down the nature of virtue. What distinguishes Bullinger from Zwingli is his ability to avoid the theocratic tendency, even when both share a high view of the magistrate. For Bullinger, oversight of the Church and the authority of the state (Romans 13) are not to be conflated.
In conclusion, the contention of one notable Roman Catholic theologian that “the sixteenth-century Protestant Reform championed grace and faith to the practical exclusion of all other instruments of divine agency” [27] is shown quite simply to be false. The magisterial reformers uniformly affirmed the role of general revelation and the natural law, even when the accent of their teaching was faith and grace. They were one with their Catholic counterparts in the conviction that Christian social ethics presupposes—and stands on—the bedrock of the natural law.
Permit me to affirm the significance of a sturdy theology of creation. Properly understood, natural theology is anchored in divine creation and our design; it is both a theological and philosophical notion. General revelation is not “autonomous”; it, too, is grace from the Creator. Special revelation and general revelation do not stand in opposition. Therefore, natural law serves as a bridge between believer and non-believer. Why? Because there exists a shared human nature.
It has been said that every generation finds a new reason to rediscover the natural law. Often that happens as a result of global disruption or socio-cultural upheaval. Perhaps in the present hour we stand in need of rediscovering the foundations of law, politics, and civil society in light of the collapse of moral foundations around us. Natural law ethics can help us. Those foundations are pre-political and pre-legal; they are intuited, in St. Paul’s words, through the law “written on the heart.” Theologically, ethically, and apologetically then, natural law needs to be a part of our repertoire as we seek to interact—faithfully and creatively—with persons in the surrounding culture.
[1] J. Daryl Charles, PhD, is a 2024/25 visiting Elshtain fellow, Institute on Religion and Democracy, as well as a senior fellow of the Center for Religion, Culture and Democracy, and serves as a contributing editor of Touchstone and Providence: A Journal of Christianity and American Foreign Policy. He is the author of twenty-three books, including, most recently, The Idea and Importance of Natural Law: Fifty Questions and Answers (Stone Tower Press, 2025), Our Secular Vocation: Rethinking the Church’s Calling to the Marketplace (B & H Academic, 2023), and (with Eric Patterson), Just War and Christian Traditions (University of Notre Dame Press, 2022).
[2] Against the Heavenly Prophets, Luther’s Works [hereafter L.W.], vol. 40, ed. Conrad Bergendorf (Philadelphia: Fortress Press, 1955), 97.
[3] Ibid.
[4] “Table Talk no. 3911: Difference between Natural and Positive Law,” in L.W., vol. 54, ed. T.G. Tappert (Philadelphia: Fortress Press, 1967), 293.
[5] How Christians Should Regard Moses, in L.W., vol. 35, ed. Theodore Bachmann (Philadelphia: Muhlenberg Press, 1960), 168.
[6] Against the Sabbatarians, L.W., vol. 47, ed. Franklin Sherman (Philadelphia: Fortress Press, 1971), 89.
[7] Ibid., p. 94.
[8] Luther, How Christians Should Regard Moses, supra n. 5, 165.
[9] Luther, Against the Heavenly Prophets, supra n. 6, 97.
[10] Martin Luther, Temporal Authority: To What Extent It Should Be Obeyed, in L.W., vol. 45, ed. Walther I. Brandt (Philadelphia: Muhlenberg Press, 1962), 128.
[11] Ibid., 127.
[12] Clyde Leonard Manschreck, Melanchthon: The Quiet Reformer (New York and Nashville: Abingdon, 1958).
[13] Robert Stupperich, Melanchthon, trans. R.H. Fischer (Philadelphia: Westminster Press, 1965), 151.
[14] The German historian Wilhelm Dilthey, Gesammelte Schriften, vol. 21:193, is cited as the source of this depiction of Melanchthon by John Witte, Jr., Law and Protestantism (Cambridge: Cambridge University Press, 2002), 122.
[15] Luther’s view of Aristotle is mixed. On the one hand, in his earlier writings Luther is quite critical—as mirrored in his well-known statement that Aristotelian thinking is to theology as darkness is to light (thesis no. 50 in his 1517 Disputation Against Scholastic Theology)—and yet, doubtless as a consequence of Melanchthon’s teaching Aristotle at the University of Wittenberg, Luther was able to express a level of appreciation for the philosopher.
[16] Melanchthon’s discussion of law and the natural law are found chiefly in Locus 6 of his magisterial work Loci Communes.
[17] Melanchthon, Loci Communes, Locus 6, 70. I am dependent on the 1543 edition of LC, translated by J.A.O. Preus and published in 1992 by Concordia Publishing House.
[18] Hereon see John Witte, Jr., and Thomas C. Arthur, “The Three Uses of the Law: A Protestant Source of the Purposes of Criminal Punishment?” Journal of Law and Religion 10, no. 2 (1993/4): 433–65.
[19] Institutes of the Christian Religion 2.8.1. Where I am citing Calvin, I am reliant on the translation of Institutes found in the LCC series, vols. 20 and 21, ed. John T. McNeill and trans. Ford Lewis Battles (Philadelphia: Westminster Press, 1960).
[20] Ibid. 2.2.22; cf. 4.10.3–4.
[21] Ibid. 2.2.13.
[22] Ibid.
[23] Ibid. 4.10.3.
[24] Ibid.
[25] Zwinglis sämtliche Werke, ed. Melchior Schuler and Johann Schulthess (Zürich: Schulthess, 1828–1842), 4.243 (my translation).
[26] The English translation is drawn from sermons of Bullinger collected and edited by Thomas Harding. See The Decades of Heinrich Bullinger (4 vols.; Cambridge: The Parker Society, 1849) 2.194 (sermon 1).
[27] Romanus Cessario, Introduction to Moral Theology (Washington, DC: Catholic University of America Press, 2001), 69 (emphasis added).
