If I find within myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world. (C. S. Lewis's Argument from Desire as it appears in Mere Christianity)
How well does this argument work? I offer myself as Exhibit A for engaging with this crisis of meaninglessness. As I searched for meaning in the first year of college, I knew at some level that there had to be more. There had to be something beyond this material world. And in Lewis I met a fellow discoverer. This brings me to something his friend and colleague at Oxford, the philosopher Austin Farrer wrote about Lewis: “We think we are listening to an argument, in fact we are presented with a vision; and it is the vision that carries conviction.” This kind of argument works for many because of Lewis’s formidable imagination. For that reason, it is a literary more than philosophical argument. It draws, as it were, more from Lewis’s degree in Lit, than his studies in Great and Mods. Here, although Lewis employs his profound analytical skills, it draws most on his creativity.
It is important here to recall his sermon, "The Weight of Glory" in that University chapel on that hot July day in 1945:
In speaking of this desire for our own far-off country, which we find in ourselves even now, I feel a certain shyness. I am almost committing an indecency. I am trying to rip open the inconsolable secret in each of you—the secret that hurts to much that you take your revenge on it by calling it names like Nostalgia and Romanticism and Adolescence….
This is not a deductive argument that begins with general premises and makes specific conclusions: “All men are mortal. Socrates is a man. Therefore Socrates is mortal.” Lewis would have learned that in the first weeks of his degree in Greats. So, if we are expecting a logical, deductive argument we will be disappointed. Sadly, I have often heard Lewis presented as one more logical (at least, in this deductive sense, “logical”) apologist. It is simply not his approach.
Instead of the deduction employed in his argument against naturalism (the previous chapter), his other apologetic arguments are better seen as a supposition (or alternatively, argument to the best explanation.)
A supposition, first of all, is not allegory. When Lewis described what he was doing with Narnia, he steadfastly denied that these stories were allegories, where each particular character or other element in the story bears an exact one-to-one correspondence with a concept. Here I’m thinking of Lewis’s own The Pilgrim’s Regress, but even more of John Bunyan’s landmark The Pilgrim’s Progress, where the Pilgrim, Christian, meets the Slough of Despair, which is not surprisingly has a one-to-one correspondence with facing despair in the Christian life. Or Lewis points to the giant who represents despair:
If Aslan represented the immaterial Deity in the same way in which Giant Despair represents Despair, he would be an allegorical figure. In reality however he is an invention giving an imaginary answer to the question, “What might Christ become like if there were a world like Narnia and He chose to be incarnate and die and rise again in that world as He actually has done in ours. So in “Perelandra.” This works out a supposition.
Lewis is drawing then a supposition, not an allegory or deductively logical argument. Indeed, as the citation above suggests, it is based on imagination. If it is an apologetic argument, it is an imaginative one. And that makes it more powerful because it “baptizes” our imagination, just as George MacDonald’s Phantastes baptized Lewis’s imagination in February 1916.
The form of this suppositional argument from desire proceeds as follows: Suppose God created this world, we can imagine that God would leave a desire for more than this world offers. We experience a longing for more than this world offers. It is reasonable to see this as pointer to God.
For readers of John Calvin (as I am), this sounds a great deal like his “sense of divinity” (or sensus divinitatis in Latin, which I’m drawn to). It is akin to Augustine’s “restless” that I quoted at the beginning of the chapter. In Calvin’s vastly influential 1559 Institutes of the Christian Religion, he wrote,
There is within the human mind, and indeed by natural instinct, an awareness of divinity.
Certainly this awareness of divinity is vague and can be open to manipulation—it can lead to a narcissistic devotion to the “God within” or the Nazi conviction that God is working through the German culture and Volk, but this sensus divinitatis also provides an important function in opening us up to God. It plays a similar role as Lewis continues to build his four-part apologetic.
Surprisingly enough—because Lewis had deep concerns about science and its misuse, as I developed in the previous chapter—contemporary cognitive sciences offer stunning, support for Lewis’s Sehnsucht or Joy. For example, neuroscientist Justin Barrett, through his work in developing a Cognitive Science of Religion (CSR), uses the findings of the cognitive sciences to argue that evolution has developed human beings so that we implicitly see purposes in events, or are predisposed toward teleology. “Evidence exists that people are prone to see the world as purposeful and intentionally ordered,” which naturally leads to belief in a Creator. For example, preschoolers “are inclined to see the world as purposefully designed and tend to see an intelligent, intentional agent behind this natural design.”
Barrett notes that the similarities with John Calvin’s sensus divinitatis He pointed to a sense of the Numinous, powerful and brooding. “Where can I go from Your presence? Where can I flee from Your spirit?” cries the psalmist in Psalm 139. It is the feeling of being out in a forest at night, knowing that no one is there, but feeling something. Often this experience can frighten us. And yet it also provides a witness to the natural knowledge of God.
To take a more prosaic view, consider the massively popular song the playbook of American movies, Somewhere Over the Rainbow: this is where our “dreams that you you dare to dream really do come true.” And additional examples for this are legion. What is powerful about this apologetic is that it doesn’t take Scripture to evoke those thoughts. They lie close.
Atheists use this tendency to impugn belief in God. In other words, suppose there is no God, and evolution has created our brains so that we cannot help but believe. Therefore no God exists. God is simply in our minds. Instead I, joining Lewis, argue that, if we suppose there is a God, the findings of cognitive neuroscience help us see that this sense of divinity is a witness to God as our Creator. We are created with openness to belief. And Joy is its signpost.
 Light on C. S. Lewis, ed. Jocelyn Gibb, 37.
 “Weight of Glory,” 200.
 29 December 1958 letter to Mrs. Hook, Letters III: 1004.
 Calvin, Institutes of the Christian Religion, 1.3.1.
 Justin Barrett, Cognitive Science, Religion, and Theology: From Human Minds to Divine Minds, Templeton Science and Religion Series (West Conshohocken: Templeton, 2011).59.
 Barrett, Cognitive Science, 71, and Born Believers: The Science of Children's Religious Belief (Free Press, 2012). This feature of early childhood has been termed “promiscuous teleology” by the psychologist Deborah Kelemen (in Barrett, Cognitive Science, 70).
 Harold Arlen with lyrics by E. Y. Harburg, Somewhere Over the Rainbow.