C.S. Lewis at the Keys

selective focus photography of black wooden piano keys

Even if you disagree with the guy, I bet you can’t outdo C.S. Lewis in his ability to illustrate an argument. His word pictures are both memorable and compelling. In Mere Christianity he gets at his arguments in many ways — from the rational and the theological to the existential, reasoning from what it feels like to be human.

I find his metaphor of piano keys and sheet music really helpful. Here’s an extended quotation from Mere Christianity that includes the keys illustration:

For example, some people wrote to me saying, ‘Isn’t what you call the Moral Law simply our herd instinct and hasn’t it been developed just like all our other instincts?’ Now I do not deny that we may have a herd instinct: but that is not what I mean by the Moral Law. We all know what it feels like to be prompted by instinct—by mother love, or sexual instinct, or the instinct for food. It means that you feel a strong want or desire to act in a certain way. And, of course, we sometimes do feel just that sort of desire to help another person: and no doubt that desire is due to the herd instinct.

But feeling a desire to help is quite different from feeling that you ought to help whether you want to or not. Supposing you hear a cry for help from a man in danger. You will probably feel two desires—one a desire to give help (due to your herd instinct), the other a desire to keep out of danger (due to the instinct for self- preservation). But you will find inside you, in addition to these two impulses, a third thing which tells you that you ought to follow the impulse to help, and suppress the impulse to run away. Now this thing that judges between two instincts, that decides which should be encouraged, cannot itself be either of them.

You might as well say that the sheet of music which tells you, at a given moment, to play one note on the piano and not another, is itself one of the notes on the keyboard. The Moral Law tells us the tune we have to play: our instincts are merely the keys.

While the objection could be made that someone could very well learn to play the piano by ear, without the aid of sheet music, Lewis’s entire argument is not limited to this one word picture. It’s a part of his cumulative case for the existence of something real, some moral law, that exists outside of ourselves. And though this illustration doesn’t settle the matter, it shows us that there is something beyond the human experience of mere instincts that is pointing us to the good, the true, and the beautiful. We hear it’s melody. We may even find ourselves dancing to its music.