Moral Law: Evolutionary Theory vs. Divine Law

Published on January 27, 2025 by Paul Blake

Is human morality nothing more than a product of evolutionary biology, or does it reflect a divine moral law "written on the heart"? This question strikes at the core of ethics and human nature, demanding a deep examination.

Skeptics often argue that our moral instincts evolved to help our ancestors survive and thrive, eliminating any need for a supernatural lawgiver. Many Christians, on the other hand, contend that the universality and profound depth of moral law point to a divine source – a law implanted in human conscience by God Himself.

This essay endeavors to explore both perspectives, beginning with the evolutionary explanation of morality, drawing on insights from thinkers like Richard Dawkins and Michael Shermer. It then delves into the Christian understanding of moral law as an objective reality grounded in God's character and made known through scripture and conscience (cf. Romans 2:14–15).

Finally, the two views will be compared, with a reasoned case made that the Christian perspective more convincingly accounts for certain moral phenomena – such as self-sacrificial love, the belief in universal human rights, and unwavering moral convictions – that purely evolutionary accounts often struggle to explain. Throughout, quotes from prominent voices, from Nietzsche to C.S. Lewis, will illustrate the contours of this long-standing debate.

The ultimate goal is a reasoned, persuasive argument, aimed at both skeptic and believer, that the Christian view provides a more coherent explanation of the moral law.

The Evolutionary Perspective on Morality

Evolutionary theory posits that our moral sensibilities are an adaptive outcome of natural selection. From this perspective, behaviors we label "moral" emerged because they helped humans, as social animals, survive and successfully pass on their genes.

Biologist Richard Dawkins, for instance, suggests that morality has "roots in our evolutionary past" stemming from the "selfish gene" and kin selection¹. In other words, traits like empathy, fairness, and cooperation provided distinct survival advantages to early human communities. Groups whose members consistently looked out for each other, supported the weak, and punished cheaters would likely outcompete those that lacked moral cohesion.

Over many generations, natural selection would thus favor a basic "moral sense" within the human species. Contemporary science writers have expanded on how evolution could hard-wire these moral instincts. Michael Shermer observes that as social primates, humans "evolved a deep sense of right and wrong to accentuate and reward reciprocity and cooperation and to attenuate and punish excessive selfishness and free riding"².

According to Shermer, our brains are essentially primed by evolution to feel good when we act kindly or justly, reinforcing reciprocity, and to feel guilt or indignation at selfish and unfair behavior, deterring actions that would undermine group cohesion. What we commonly call conscience, in this view, functions as the psychological mechanism through which evolution encourages pro-social behavior.

Even behaviors that appear purely altruistic can be explained in terms of genetic self-interest: evolutionary biologists theorize that kin selection leads us to protect relatives (thereby indirectly ensuring our genes survive), while reciprocal altruism leads us to help non-relatives with the implicit expectation that the favor will be returned in the future³. By these lights, moral norms like "help your neighbor" or "protect the vulnerable" emerged because they demonstrably benefited our ancestors' survival in tightly knit communities.

The Naturalistic Approach

Evolutionary thinkers also argue that morality does not necessarily require belief in God or any supernatural realm; it can be fully naturalized. For example, psychologist Steven Pinker and others have pointed to studies of animals (like primates) that exhibit empathy, fairness, and peacemaking, suggesting these are evolutionary precursors of human ethics.

The implication is that human morality evolved continuously from behaviors in earlier animals, rather than being miraculously implanted at a specific point. Even our visceral sense of moral outrage at cheaters or admiration for heroes might be seen as evolutionary drives to punish antisocial behavior and reward group-beneficial behavior.

However, evolutionary approaches vary considerably in how they interpret the ultimate status of moral values. Some proponents of evolutionary ethics maintain that moral feelings, though rooted in biology, still point to real, objective values like well-being that reason can then build upon. For instance, Sam Harris has famously argued that science can ground an objective morality by measuring which actions contribute to "the well-being of conscious creatures"⁴.

On this account, evolution gave us the capacity for moral reasoning, and we can use that capacity to discover ethical truths (such as the inherent wrongness of cruelty) by observing what genuinely promotes human flourishing. Shermer similarly suggests that certain core moral principles (like fairness or liberty) can be justified as natural human values that transcend any one culture – products of our common nature as social beings.

The Problem of Moral Objectivity

Other thinkers, however, are far more skeptical about morality's objectivity if it is purely a product of evolution. Philosopher Michael Ruse bluntly argues that "morality is a collective illusion foisted upon us by our genes"⁵. This admission reveals the inherent fragility of grounding morality in mere evolutionary convenience. If moral truth is simply a useful fiction, it cannot provide the firm foundation required for universal human rights or justice.

Echoing this perspective, biologist E.O. Wilson once wrote that "ethics is an illusion fobbed off on us by our genes to promote cooperation"⁶. The tension among evolutionary theorists, then, is whether moral norms are only bio-social conventions or whether they reflect deeper, objective truths accessible through reason and experience.

Friedrich Nietzsche's critique of morality is often cited by skeptics in this vein: he claimed that "morality is just a fiction used by the herd of inferior human beings to hold back the few superior men"⁷. Nietzsche, writing in the 19th century before modern evolutionary psychology, believed that what people call "morality" – especially Christian morality – was a human invention, a tool by which the weak could restrain the strong.

His stark view anticipated the notion that without a divine foundation, moral rules might ultimately reduce to power struggles or mere survival tactics. Indeed, if nature is "red in tooth and claw" and only the fittest survive, some might ask why we ought to be compassionate at all.

The philosophy of Social Darwinism historically took that cynical route, arguing that aiding the weak was against nature's way. While evolutionary science itself does not endorse Social Darwinism – most evolutionary thinkers today strongly repudiate using "survival of the fittest" as a moral guide – the mere fact that nature has produced both caring and cruel behaviors highlights a key limitation.

As T. H. Huxley (a champion of Darwin) pointed out in his 1893 work, Evolution and Ethics, nature can explain how we came to have impulses for both "good" and "evil," but "as the immoral sentiments have no less been evolved" as the moral ones, "the thief and the murderer follow nature just as much as the philanthropist"⁸.

In short, evolution alone can describe the origin of our instincts, but it struggles to prescribe an authoritative moral law or tell us why we should choose good impulses over bad ones. This fundamental challenge sets the stage for the alternative explanation: that morality is grounded not in mere survival advantage but in the purpose and character of a divine Creator.

The Christian Perspective: Divine Moral Law

Christian teaching has long held that moral law is real, objective, and intricately woven into the fabric of human nature by God. Far from being an evolutionary accident or a mere cultural construct, morality in this view reflects the very character of a just and loving God who made humans in His image.

Thus, humans possess an innate sense of right and wrong – a conscience – that inherently points to a universal moral order. The Apostle Paul articulated this idea nearly two thousand years ago in the New Testament: "When Gentiles, who do not have the [Mosaic] law, do by nature things required by the law... they show that the requirements of the law are written on their hearts, their consciences also bearing witness" (Romans 2:14–15 NIV)⁹.

In this biblical passage, Paul argues that even those who never explicitly received God's commandments (such as non-Jews without the Hebrew law) still possess an inner law. This "law on the heart" implies a God-given moral compass that transcends any one society or era.

Historical Christian Thought

Christian thinkers across the ages have expanded on the notion of an implanted moral law. St. Augustine, in the 4th century, taught that true justice and moral truth are rooted in God's eternal law. Human beings, by virtue of being created by God, carry an imprint of that eternal law in their very being.

Augustine famously wrote in his Confessions that God's law is "written in men's hearts, which not even ingrained wickedness can erase"¹⁰. Even a thief, he noted, does not want to be stolen from – clear evidence that in his heart he recognizes theft as wrong.

In Augustine's analogy, the impression of God's law on our hearts is like a king's signet ring pressed into wax: the wax bears the image of the ring without becoming the ring itself. Likewise, humans bear the image of God's righteousness without becoming divine themselves. The natural law (our moral understanding) is therefore "an image of the eternal law writ in the heart of man, impressed there by the Lord who made him"¹¹.

This view, shared by many Church Fathers and later by Thomas Aquinas, sees conscience not as an evolved quirk but as compelling evidence of a higher Lawgiver. Right and wrong are objective realities founded in God's nature (e.g., God's holiness, justice, love), and we discern them, albeit imperfectly, through the faculties God gave us – reason and conscience enlightened by divine revelation.

C.S. Lewis and the Modern Defense

C.S. Lewis, writing in the 20th century, provided a powerful modern articulation of the Christian concept of moral law in works like Mere Christianity and The Abolition of Man. In Mere Christianity, Lewis refers to the "Law of Human Nature" – the curious and persistent idea that humans across cultures possess an innate sense of how they ought to behave, and this idea is remarkably difficult to shake¹².

He, like Augustine, took this universal moral law as a crucial clue to the meaning of the universe, suggesting it strongly points to a moral Creator. In The Abolition of Man, Lewis further defends the existence of objective values and what he calls "the Tao" – a universal moral law that he demonstrates all significant cultures have acknowledged in some form.

He meticulously collected examples of core moral principles from diverse civilizations (Ancient Egyptian, Norse, Chinese, Hindu, etc.) and showed their striking commonality: virtues like honesty, charity, and duty to one's family are upheld nearly everywhere¹³. Rather than seeing this as merely a product of evolutionary convergence, Lewis sees it as compelling evidence that objective value is real and knowable – humanity fundamentally shares some access to moral truth.

The Consequences of Abandoning Objective Morality

Moreover, Lewis warns that abandoning belief in this objective moral law has grave consequences. If we treat all values as mere preferences or evolutionary byproducts, we fundamentally undermine the basis of moral judgment itself. In Lewis's vivid phrase, we risk creating "men without chests" – individuals educated to have keen intellects and voracious appetites, but utterly lacking a moral heart to moderate between them¹⁴.

In the absence of a higher moral law (the Tao), what is to stop those with power from simply imposing their will? Lewis cautions that moral relativism ultimately reduces ethics to a raw struggle of wills: "the question is not what is right or wrong, but which group has the most power to impose its will"¹⁵.

By stark contrast, the Christian vision upholds that right and wrong are determined by God's design and commandments, providing a necessary check on human power and a moral compass for human conduct that does not bend to might or transient majority opinion.

In sum, the Christian perspective presents moral law as real, objective, and transcendent. Moral truths (such as "murder is wrong" or "charity is good") are not mere animal instincts or social contracts; they are perceived by us because, in reality, there exists a moral order given by God.

This does not deny that biology or culture influence how we practice morality, but it asserts that behind our intuitive moral convictions lies a source beyond nature – namely, the Creator who made us with a purpose. As the theologian Dinesh D'Souza put it, "the presence of a universal moral law is best explained by a universal Moral Lawgiver" – a common summary of the moral argument for God.

Whether one agrees or not, this view boldly asserts that evolution alone cannot fully account for the depth, breadth, and inherent authority of the moral law that humankind universally recognizes.

Comparing the Two Perspectives

Both evolutionary theory and Christian theology offer valuable insights into why human beings are moral creatures. The evolutionary perspective compellingly explains how certain pro-social behaviors and instincts could have arisen through natural selection. It sheds light on the biological and psychological underpinnings of why we feel empathy, outrage at injustice, or a fundamental sense of fairness.

However, when it comes to the full reality of the moral law, the Christian perspective provides a more complete and coherent account. The Christian view affirms the insights of science about our social and biological nature, yet it goes further – it accounts for the normative dimension of morality, the fact that moral law inherently binds us and often calls us to a standard higher than mere survival.

It explains why humans universally perceive some actions as inherently right or wrong, even when doing what is right brings no immediate advantage or even significant personal cost. It grounds the lofty ideals of human rights and dignity in the solid reality of God's purpose and love, rather than in the shifting sands of evolutionary utility.

In Christian apologetic terms, evolution may describe the mechanism or organism of morality, but God is the origin of morality.

Conclusion

In the final analysis, the question is not which view dismisses the other, but which view can best synthesize all the evidence of our moral experience. Can cold evolutionary history alone fully explain a Mother Teresa or a Martin Luther King Jr., or the persistent, stubborn prick of conscience in each of us that demands we do what is right even when it is difficult?

Or does the existence of such profound moral beauty and conviction point to a higher Lawgiver beckoning us toward the good? This essay has argued that while evolution can illuminate the biological conditions that shape our moral faculties, it is the Christian understanding of divine moral law that best explains the inherent content and authoritative nature of the moral law itself.

As C.S. Lewis observed, denying the reality of objective moral values leads not to liberation but to the "abolition of man" – a dehumanizing nihilism. But affirming that there is a transcendent moral lawgiver restores confidence that our moral striving is not in vain – that when we choose integrity over convenience, love over selfishness, and truth over lies, we are aligning ourselves with the very grain of the universe, not fighting against a meaningless void.

The Christian view of moral law endows our ethical life with a significance and coherence that evolutionary theory by itself simply cannot muster. It declares that the moral law within us is not a cosmic accident, but a profound clue to the very nature of reality – a reality in which, ultimately, "the light shines in the darkness, and the darkness has not overcome it" (John 1:5).

Sources Cited

  1. Richard Dawkins, The Selfish Gene (Oxford University Press, 1976), Introduction.

  2. Michael Shermer, The Moral Arc: How Science and Reason Lead Humanity Toward Truth, Science, and Freedom (Henry Holt and Co., 2015), Chapter 1.

  3. For a general overview of these concepts in evolutionary biology, see, for example, Robert L. Trivers, "The Evolution of Reciprocal Altruism," The Quarterly Review of Biology 46, no. 1 (March 1971): 35-57.

  4. Sam Harris, The Moral Landscape: How Science Can Determine Human Values (Free Press, 2010), Chapter 1.

  5. Michael Ruse, "Evolutionary Ethics: A Phoenix Arisen," in Evolutionary Ethics and Its Critics, ed. Max Meuller and Thomas J. Schopf (Cambridge University Press, 1999), 230.

  6. Edward O. Wilson, On Human Nature (Harvard University Press, 1978), 4.

  7. Friedrich Nietzsche, On the Genealogy of Morality (1887), First Essay, Section 10.

  8. Thomas Henry Huxley, Evolution and Ethics (Macmillan and Co., 1893), Chapter 2.

  9. Romans 2:14–15, New International Version.

  10. Augustine, Confessions, Book 10, Chapter 20.

  11. A concept drawn from Augustine's teachings on natural law and eternal law, often expressed in works like On the Spirit and the Letter.

  12. C.S. Lewis, Mere Christianity (HarperOne, 1952), Book One, Chapters 1-2.

  13. C.S. Lewis, The Abolition of Man (HarperOne, 1944), Chapter 1, "The Tao."

  14. C.S. Lewis, The Abolition of Man (HarperOne, 1944), Chapter 1, "The Abolition of Man."

  15. C.S. Lewis, The Abolition of Man (HarperOne, 1944), Chapter 2, "The Way."