Day 3 of 28
The Reality of the Moral Law
More Than Instinct, More Than Convention
Scripture Readings
Today's Reading
Read Psalm 19:7-9: "The law of the Lord is perfect, reviving the soul; the testimony of the Lord is sure, making wise the simple; the precepts of the Lord are right, rejoicing the heart; the commandment of the Lord is pure, enlightening the eyes."
Then read James 1:25: "But the one who looks into the perfect law, the law of liberty, and perseveres, being no hearer who forgets but a doer who acts, he will be blessed in his doing."
Reflection
Lewis now addresses a subtler objection: perhaps the moral law is not a real law at all but merely an instinct, like the maternal instinct or the survival instinct. Maybe "conscience" is just another biological drive.
Lewis dismantles this with a powerful analogy. We have many instincts — self-preservation, compassion, the herd instinct, the desire for pleasure. Sometimes they conflict. When you see someone drowning, your instinct for self-preservation says "stay safe," while your compassion says "help." The moral law is the thing that adjudicates between them, telling you which instinct to follow in this particular situation.
"The Moral Law tells us the tune we have to play: our instincts are merely the keys."
An instinct cannot judge between instincts any more than one player on a football pitch can simultaneously be the referee. The moral law stands above our instincts, directing them — which means it cannot be reduced to any one of them.
Lewis sharpens the point further: the moral law characteristically tells us to follow the weaker impulse, not the stronger. When you feel the pull to run from danger but your conscience says stay and help, the moral law is overriding the stronger instinct in favor of the weaker one.
"If two instincts are in conflict, and there is nothing in a creature's mind except those two instincts, obviously the stronger of the two must win. But at those moments when we are most conscious of the Moral Law, it usually seems to be telling us to side with the weaker of the two impulses."
This is not how instincts work. Instincts push; the moral law commands. The difference matters enormously.
Going Deeper
Psalm 19 describes the law of the Lord as "perfect" and "reviving" — not as a cold set of rules but as something life-giving. James calls it "the perfect law of liberty." These are remarkable phrases. A law that liberates. A command that revives.
Lewis is building toward the same insight: the moral law is not a cage but a compass. It tells us what kind of creatures we are and what kind of life we were made for. To follow it is not to lose freedom but to find it.
Key Quotes
“The Moral Law tells us the tune we have to play: our instincts are merely the keys.”
“If two instincts are in conflict, and there is nothing in a creature's mind except those two instincts, obviously the stronger of the two must win. But at those moments when we are most conscious of the Moral Law, it usually seems to be telling us to side with the weaker of the two impulses.”
Prayer Focus
Thanking God that His moral law is not a burden but a guide — perfect, reviving the soul, and making wise the simple
Meditation
Think of a time your conscience told you to do the harder thing. Was that voice just instinct — or something more?
Question for Discussion
Lewis argues the moral law often tells us to side with the weaker instinct against the stronger one. Can you think of a recent example where your conscience urged you toward the harder path? How does this pattern challenge the idea that morality is just biology?