If God Wrote the Moral Law, Why is it so Often Ambiguous?

A response to C.S. Lewis’s Mere Christianity, Book I

The Creation of Adam, by Michelangelo (Wikimedia Commons)

C.S. Lewis’s celebrated work Mere Christianity opens with an argument for the existence of God, or at least for Something beyond and above the material universe, that’s rooted in human beings’ moral intuitions.

In this essay, I’ll explain Lewis’s argument and examine why it fails to support his conclusion. I’ll only cover Book I of Mere Christianity here. I plan to tackle Books II and III in subsequent articles.

The Law of Human Nature

Our experience of right and wrong reveals two undeniable facts. First, right and wrong feel objective. When we accuse others of wrongdoing we expect them to acknowledge the validity of the norm they’ve transgressed. When we are accused of wrongdoing, we try to explain why some exception to the norm applies. We don’t deny the norm itself.

And second, none of us is perfect. We all fail to live up to the standard of right and wrong that we and others in our community accept.

Lewis finds this second point particularly compelling because it highlights a crucial difference between our sense of right and wrong — or what Lewis calls the Law of Human Nature — and the Laws of Nature that govern…