03/25/2015 01:57 pm ET Updated May 25, 2015

The Meaning of Goodness

For those who know C.S. Lewis as the author of the Chronicles of Narnia books, it may be a surprise that the he became famous for his wartime radio addresses to the British people during WWII. As Britain was hunkered down to endure periodic air raids by the Nazis, two figures offered them hope and solace over the radio: Winston Churchill and C.S. Lewis. Churchill spoke about the need for fortitude and courage against Nazi aggression.

By contrast, with wit and clarity, Lewis talked, in amiable terms Socrates himself might have admired, about simple and humble choices between right and wrong. These talks were collected in a wonderful volume called Mere Christianity.

In times of "existential" peril, as Britain's fate hung in the balance, step by step, Lewis clearly explained how a sense of moral obligation can't be explained by what he called instincts of self-preservation or allegiance to the herd. For Lewis, and for anyone who listened to his arguments, the moral imperative is a law human beings can neither invent nor escape--and, as a result, leaves us always feeling inadequate and slightly ashamed. We don't think it up. We live in its benevolent shadow. In other words, distinctions between right and wrong are innate and self-evident, and are, in human affairs, similar to the law of gravity in physics.

And yet, unlike the laws of physics, it doesn't describe the nature of what can be observed in most human behavior -- since most of us rarely abide by it perfectly in our choices -- but rather a law of what "ought to be." In other words, it describes how we know we should behave, but often don't. This fascinated Lewis and became for him evidence of God, though his thoughts on morality itself didn't depend on a faith in God.

He offered one example: you hear someone drowning and calling for help. You have both the urge to dive into the water, but you want to stay on dry land to avoid the risk. Both are sensible choices, in practical terms -- either way, someone is likely to survive, therefore the human race can go on. In fact, in terms of pure survival, it makes more sense to let the person drown. That way at least one of you is certain to survive. Yet, just standing there, you feel ashamed of yourself. It's how your innate sense of right and wrong come into play by reminding you of a moral law that bears down on your deliberations and urges you to do something you don't want to do.

This isn't built into your behavior as an impulse. More often than not, it halts your impulses. Against herd instinct and self-preservation, it's a third, non-instinctive imperative that opens up the struggle of free choice. Lewis told the British people the meaning of human life resides in this moral struggle -- and it explained why they, in their vulnerability, were superior to their Nazi enemies.

Choosing to do the right thing in small ways, for him, strengthened an individual for making the far more consequential decisions, once they arrive. Every choice counts, and, for Lewis, these choices are where the value of a human life takes shape.

What I love about Lewis is how his conversion to Christianity seems to have followed logically from this perception of the moral law in human nature -- not the other way around. For him, this moral law comes from somewhere other than common patterns of human behavior. It is a gift that can't be explained away by the urge to survive as a group or as an individual -- and he traced that gift back to God.

When he presented these simple, air-tight arguments to the British people -- about choices they all faced in times of peace, as well as war--they responded with thousands of letters to him and huddled around their radios, thirsting to hear words that gave their embattled lives a sense of purpose and value. As Air Chief Marshal Sir Donald Hardman wrote:"The war, the whole of life, everything tended to seem pointless. We needed, many of us, a key to the meaning of the universe. Lewis provided just that."

Peter Georgescu is the author of The Constant Choice. He can be found at Good Reads.