Mere Christianity

01The Curious Law of Human Nature

Every single day, we hear people arguing with one another. Whether it is a couple bickering in a coffee shop, coworkers disputing credit for a project, or children fighting over a toy on the playground, the underlying structure of these quarrels is always the same. One person will say something like, "How would you like it if anyone did the same to you?" or "That is my seat, I was there first," or even "Come on, you promised." The most fascinating aspect of these everyday disputes is not that people get angry, but rather the way they try to prove the other person is in the wrong. They do not merely state that the other person's behavior is inconvenient to them. Instead, they appeal to an invisible, universally understood standard of behavior that they fully expect the offending party to know about. This brings us to a profound realization: human beings all over the earth have this curious idea that they ought to behave in a certain way, and they cannot really get rid of it. C.S. Lewis calls this the Law of Human Nature. In centuries past, thinkers simply referred to it as the Law of Nature. When they used that term, they did not mean the laws of physics, like gravity or thermodynamics. A stone does not have a choice about whether it will obey the law of gravity; if you drop it, it must fall. A tree does not choose whether to grow according to the biological laws of nature. But a human being is entirely different. A human being is subject to all the biological and physical laws of the universe, but there is one law that is unique to humanity—a law that we can choose to obey or choose to break. Some might quickly object to this idea, arguing that different cultures and different ages have had vastly different moralities. People often point to history and say that what was considered right in ancient Sparta is completely different from what is considered right in modern-day London or Tokyo. However, Lewis thoroughly dismantles this objection by asking us to look a little closer at the evidence. The differences in cultural morality are actually quite superficial when compared to their overwhelming similarities. Think about it thoughtfully. Has there ever been a society where cowardice in battle was celebrated as a virtue? Has there ever been a civilization that rewarded people for double-crossing those who have been kindest to them? You can go to any library, pull out texts from ancient Egypt, Babylon, Rome, or China, and you will find the exact same core values being taught. Selfishness has never been admired. Murder is universally condemned. The specific applications of the rules may slightly vary—such as whether a man is allowed one wife or four—but the fundamental framework of right and wrong remains astonishingly constant. Another common objection is that this so-called moral law is nothing more than our herd instinct. We are biological creatures, after all, and biology dictates that we have certain instincts to preserve the species, such as a mother's love for her child or the instinct to rescue a person in danger. Therefore, some argue, the feeling of "right and wrong" is just a biological urge that has developed over millions of years. But Lewis points out a critical flaw in this reasoning. We all have instincts, but the moral law is not an instinct itself; it is the thing that judges between our instincts. Consider a scenario where you hear someone crying for help in a burning building. You will likely feel two conflicting instincts at exactly the same time. The herd instinct will urge you to run in and help the person. The self-preservation instinct will scream at you to run away and save yourself. If human behavior were driven entirely by instinct, the stronger instinct would naturally win every single time. Yet, in that exact moment of crisis, you feel a third, distinct voice inside your mind. That voice tells you that you ought to suppress the instinct to run away, and you ought to encourage the instinct to help. This third voice cannot be one of the instincts itself. The thing that tells you which note to play on a piano cannot be one of the notes on the keyboard. The Moral Law is like the sheet music that directs our biological impulses, telling us when to strike the key of self-preservation and when to strike the key of altruism. Furthermore, if the moral law were simply a herd instinct, then the "good" instinct would always be the right one to follow. But there is no instinct we have that is always good. Sometimes a mother's love for her child—a beautiful instinct—can become so blinding that she acts unfairly toward other children. In that case, the moral law must step in and tell her to suppress her maternal instinct for the sake of justice. Finally, people argue that this moral law is just a social convention, something put into our heads by education and society. We learn the alphabet and we learn to drive on a specific side of the road because society taught us to do so. These are purely man-made conventions. But we also learn mathematics from our teachers. Is mathematics merely a human invention that could be different in another country? Of course not. Two plus two equals four, regardless of culture or upbringing. The Law of Human Nature belongs to the same category as mathematics. The ultimate proof of this is how we judge human progress. We all believe that the morality of the world can improve or deteriorate. We believe that abolishing slavery was a moral improvement. But if the moral law is just a subjective social convention, then no set of rules is objectively better than another. The very fact that we can say one society's morality is superior to another's proves that we are comparing both of them to a real, external standard. We are measuring them against a True North. If there is no True North, then progress is a meaningless concept. The undeniable reality is that we are forced to believe in a real Right and Wrong. Yet, despite knowing this law exists, we humans consistently fail to keep it. We break the rules we expect others to follow, leaving us with a profound mystery to solve in the next phase of our journey.