“The key to my books is Donne’s maxim, 'The heresies that men leave are hated most.' The things I assert most vigorously are those I resisted long and accepted late.”
What is he saying? Is he arguing that this sense of transcendence—or better, this desire for it, which Lewis calls “Joy”—proves God?
No, at least not as a deductive proof. Instead Lewis is making a suppositional argument here: We do not fully understand the desire for something beyond (or Joy) itself, but it opens to a wider metaphysical conclusion, one that points to God who created us.
Or more systematically, 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.
“Everyone who is seriously involved in the pursuit of science becomes convinced that a spirit is manifest in the laws of the Universe—a Spirit vastly superior to that of man.” Albert Einstein
And my argument here is that Joy—in Lewis's sense—historically and philosophically, leads to science. I'll leave it there for now.