The Law Written on the Heart

For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves: which shew the work of the law written in their hearts, their conscience also bearing witness. ROMANS 2:14–15

When the BBC asked Lewis in 1941 to speak on the radio about the Christian faith, he made an unexpected choice. He did not begin with God, or with Christ, or with the Bible. He began with quarrelling. The first series of talks, later the opening section of Mere Christianity, started from something every listener did every day, and asked what it implied about the universe.

The appeal to a standard

Listen to people quarrel, Lewis said in substance, and you will notice something curious. They do not simply say that they dislike what the other person has done. They say that it is unfair. They complain that a promise has been broken, that someone has jumped the queue, that a debt has not been repaid. And the person accused rarely replies that fairness does not matter. He tries to show that what he did was not really unfair after all, or that there was a special reason for it. Both sides, in other words, are appealing to a standard of behaviour that they expect the other to know and accept.

This standard, which the old writers called the law of nature, is not peculiar to one people or one age. Lewis, who knew the moral literature of many ancient civilisations, insisted that the differences between them have been exaggerated. Peoples have drawn the circle of obligation in different places, and arranged marriage and property in different ways; but no people has honoured the traitor, praised the coward or held that a man owes nothing to anyone but himself. The details vary; the outline is remarkably constant.

He hath shewed thee, O man, what is good; and what doth the Lord require of thee, but to do justly, and to love mercy, and to walk humbly with thy God? MICAH 6:8

Not instinct, not convention

Lewis then dealt with two common ways of explaining the moral law away. Some say it is merely herd instinct — the impulses evolution has given us to help the species survive. But, he replied, we often feel two impulses pulling against each other — the urge to help someone in danger, and the urge to keep ourselves safe — and the moral law is the thing that tells us which of them to follow. It stands to our impulses rather as a conductor stands to the players in an orchestra. It cannot be simply one more of them.

Others say the moral law is only a social convention, taught to us by our parents and our schools, like the rules of a game. But conventions can differ without one being better than another, while we do in fact judge some moral codes to be better than others. We say that a nation that abolished slavery made moral progress. If morality were merely convention, there could be no such thing as progress, only change. The very idea that one people’s morals can be better than another’s implies a real standard against which both are measured.

Everyone fails

The second fact Lewis drew out was as plain as the first. Not only do all people know this law; all people break it. None of us keeps even our own standards, let alone the standards we expect of others. And we are remarkably good at excusing ourselves. When we fail, we blame our tiredness, our upbringing, our circumstances. The very energy we put into excuses shows how much we believe in the law we are breaking.

For all have sinned, and come short of the glory of God. ROMANS 3:23

Everything else, Lewis believed, has to start from these two facts: that we know how we ought to behave, and that we do not behave that way.

Something behind the law

What follows from this? Lewis argued that the moral law is not like the laws of nature, such as gravity, which simply describe what matter does. Stones do not choose to fall, and nobody blames them for doing so. The moral law describes not what we do but what we ought to do, and we fail to do it. It is a law pressing on us from outside, a command. And a command implies someone who commands. The best evidence we have of what lies behind the universe, Lewis suggested, is not the stars or the mountains, which tell us that whatever made them is very great, but this law inside us, which tells us that whatever made us cares intensely about right and wrong — about fairness, unselfishness, courage, good faith and honesty.

The heavens declare the glory of God; and the firmament sheweth his handywork. PSALM 19:1

The law of the Lord is perfect, converting the soul: the testimony of the Lord is sure, making wise the simple. PSALM 19:7

He was careful not to claim too much. This argument does not yet bring us to the Christian God. It brings us to a Power behind the universe that is personal — a will with purposes of its own — and that is concerned with how we behave. But that, Lewis said, is precisely what makes it disturbing. If such a Power exists, and if we have broken its law, then we are in trouble. Christianity, he concluded, has nothing to offer a person who has not felt that trouble. It is the medicine for a disease, and a man who does not believe he is ill will have no use for a doctor.

They that be whole need not a physician, but they that are sick. MATTHEW 9:12

The Abolition of Man

Lewis returned to the moral law, from a different angle, in a short book of 1943 called The Abolition of Man. It began as a set of lectures prompted by a school textbook on English, which taught children, without quite saying so, that all statements of value are merely statements about the speaker’s feelings. To call a waterfall sublime, the textbook implied, is only to report one’s own emotions. Lewis argued that this apparently harmless teaching was poison. If no value is real, then courage, honour and self-sacrifice are only feelings, and the young will be trained to feel nothing in particular about them. A society that teaches its children that goodness is merely a matter of taste, he warned, cannot then complain when they behave as though it were.

Against this he set what he called, by an ancient Chinese name, the Tao — the shared recognition, found in the moral teaching of every great civilisation, that some things really are good and others really are evil, and that the human heart ought to be trained to love the one and hate the other. At the end of the book he gathered illustrations from Hebrew, Greek, Roman, Chinese, Indian, Norse and Christian sources to show how widely that recognition has been shared. His warning was that a generation which set itself above the moral law, treating it as something to be engineered rather than obeyed, would not liberate humanity; it would hand power over humanity to whoever did the engineering. His novel That Hideous Strength puts the same warning into story.

Woe unto them that call evil good, and good evil; that put darkness for light, and light for darkness; that put bitter for sweet, and sweet for bitter! ISAIAH 5:20

Weighing it

Lewis’s moral argument has been one of the most widely used tools of Christian apologetics for eighty years, and it stands firmly on the ground Paul lays down in Romans 1 and 2: that God has left His witness in creation and in conscience, so that men are without excuse. Evangelical readers can receive it with gratitude.

Two cautions are in order. First, the argument establishes a moral Lawgiver, not a Saviour. Lewis knew this and said so; but readers who stop at the first section of Mere Christianity have only half the message. The law can show us our sin; it cannot take it away.

Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin. ROMANS 3:20

Second, conscience is a true witness but a damaged one. The moral law is written on every heart, but sin has blurred the writing, and the natural moral sense can be deadened, distorted or trained into error. That is why God gave His law in words, and why He sent His Son. Lewis would have agreed; but the reader should remember that conscience needs the Scriptures to correct it, not only to confirm it.

FOR REFLECTION AND ACTION

1. Recall the last time you complained that something was unfair. What standard were you appealing to, and where did you think it came from?

2. Name one point at which you consistently fail to keep your own moral standards. How have you been excusing it?

3. Read Romans 1:18–2:16 and notice how Paul describes the witness of creation and conscience.

4. Think about what the children around you are being taught about right and wrong. Is goodness presented as real, or as a matter of taste?

5. Thank God that the law which condemns you points you to the Saviour who fulfilled it.

A PRAYER

Holy God, You have written Your law on my heart, and I have broken it again and again.

I have known what is right and not done it, and I have spent my strength making excuses.

Thank You that You did not leave me with only a law to condemn me, but sent Your Son to keep it in my place and to bear the penalty of my failure.

Write Your law more deeply in me by Your Spirit, and make me love what You love, through Jesus Christ. Amen.