Can Evolution Explain Universal Moral Law?

‘Supposing you hear a cry for help from a man in danger. You will probably feel two desires—one a desire to give help (due to your herd instinct), the other a desire to keep out of danger (due to the instinct for self- preservation).

But you will find inside you, in addition to these two impulses, a third thing which tells you that you ought to follow the impulse to help, and suppress the impulse to run away.

Now this thing that judges between two instincts, that decides which should be encouraged, cannot itself be either of them.

You might as well say that the sheet of music which tells you, at a given moment, to play one note on the piano and not another, is itself one of the notes on the keyboard. The Moral Law tells us the tune we have to play: our instincts are merely the keys.‘ – C.S. Lewis, Mere Christianity

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Morality as a Clue to God’s Existence

Lewis’s piano analogy helps us understand why this universal moral sense is evidence for God. Just as the notes on a piano don’t create themselves, neither do the moral standards we intuitively follow. Music requires a composer, and similarly, morality requires a moral lawgiver. The fact that we have an internal guide—our conscience—that tells us what is right and wrong points beyond ourselves to a Creator who wrote that law into our hearts.

If moral law was merely a human invention, like traffic laws or fashion trends, it would change drastically over time and between cultures. Yet, no matter where you go in the world, people agree on certain moral truths. We might argue about the details, but no one truly believes that unprovoked cruelty is “good” or that selfishness is a “virtue.”

This shared moral framework suggests that there is a higher standard outside of us, a law we are all aware of but didn’t create. The existence of this moral law points to the existence of a moral lawgiver—God.

What Is The Moral Law?

Think of moral law as the unwritten rules that help us figure out what’s right and wrong in life. It’s like a guide for how we should treat others and live in a way that’s good for ourselves and for society. These rules often come from things like religious teachings, cultural traditions, or just shared ideas about what’s fair and kind.

For example, we all generally agree that things like telling the truth, being fair, and respecting others are important, while lying, stealing, or hurting people are wrong. So, moral laws are those guiding principles that help us navigate life’s choices and interactions in a way that leads to a better, more just world.

C.S. Lewis’s analogy about a universal moral law suggests that without a moral lawgiver (God), the basis for determining right and wrong becomes shaky. In the absence of a higher authority to establish objective moral standards, society is left to rely on human consensus, cultural norms, personal preferences, or even power dynamics to arbitrate morality.

Who Was Right: Hitler or Mother Theresa?

If we ask, “Who is right—Hitler or Mother Teresa?” and we try to answer that without appealing to any objective moral standard, we’re left in a precarious position.

If we try to judge based on something like evolutionary instinct or the survival of the species, it’s still just one standard among many, and it can be easily questioned. Here’s how this plays out:

The Evolutionary Instinct to Survive (Herd Mentality)

If one argues that the evolutionary instinct to preserve life is what makes Mother Teresa right and Hitler wrong, we run into the issue of why survival or altruism should be inherently better than power, domination, or destruction.

In the natural world, evolution doesn’t have a built-in “moral code.” Some species survive through cooperation, others through competition or even predation. For example, if survival of the fittest were the ultimate standard, one might argue that Hitler’s ideology was a warped attempt to assert a form of “superiority” for his people, which he believed would lead to their dominance.

If “survival of the fittest” were the ultimate standard for determining right and wrong, then Hitler’s actions could be argued, from a purely evolutionary standpoint, as an attempt to assert superiority and ensure the survival of his people. This is a frightening prospect because it justifies atrocities in the name of survival and power. The logic of “might makes right” underpins such thinking, meaning that if you are able to dominate and survive, you are justified in doing so.

And besides by what standard can you argue that survival is ‘better’ than non-survival of a species? if survival is just a biological process, there is no inherent moral imperative behind it. It’s simply what happens. Who’s to say that survival is better than extinction, or that selflessness is better than selfishness?

Without a divine creator bestowing inalienable rights upon each unique individual, there is no basis upon which one can argue for the innate value of human life.

Moral Relativism Fails

Without an objective standard, someone could argue that Hitler was right according to his own beliefs, and Mother Teresa was right according to hers. If moral truth is merely a human construct, then we can’t definitively say that one was “right” or “wrong”—just that they had different perspectives.

However, this is highly unsatisfying because it doesn’t align with the deep moral intuition most people have. There is a sense within nearly all human societies that certain things—like genocide—are objectively wrong. But without a universal standard, we can only say that we prefer altruism over domination. The problem is, preference is not the same as moral truth.

Objective Morality Needs God

This is where the need for an objective moral lawgiver (God) comes into the discussion. If we believe there is a standard above human opinion and evolution, then we can say that Hitler’s actions were objectively wrong and that Mother Teresa’s were objectively right, not just because of survival, consensus, or power, but because these actions align or conflict with a universal, transcendent moral law.

In the Christian worldview, this moral law comes from God, who is the ultimate source of good. According to this standard:

• Hitler’s actions were wrong because they involved the violation of the sanctity of life, hatred, and cruelty, which go against God’s command to love and protect life.
• Mother Teresa’s actions were right because they aligned with the values of selflessness, love, and service, reflecting the nature of God’s care for humanity.

Questioning Survival as a Standard

If someone argues that “survival” is the ultimate standard, we can easily question it by asking, “Who says survival is better than extinction?” In the natural world, there’s no intrinsic “good” or “bad” attached to survival; it’s just what organisms do. Without a higher moral framework, saying that survival is superior is just as arbitrary as any other standard.

Thus, the real question becomes: what kind of moral framework allows us to say with confidence that selflessness, like Mother Teresa’s, is superior to cruelty and hatred, like Hitler’s? Lewis and many others argue that only the existence of an objective, universal moral law—grounded in a moral lawgiver (God)—gives us the tools to judge right from wrong in a meaningful way.

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