The Medieval Mind of C. S. Lewis: How Great Books Shaped a Great Mind

by Jason M. Baxter

Lewis develops this thought experiment of transposition in order to construct an explanatory model for how higher spiritual realities are related to lower sensible realities. As my emotions are to my physical sensations, so too is the “higher world” to the natural world of time and nature: it fills this world and makes it seem “too full,” “too dense” to not point beyond itself. This, then, is what is at stake when considering Lewis’s admiration for medieval cosmology, because for him the medieval universe was not just a system of exploded scientific beliefs, but the natural, icon of transposition, the greatest example of the spiritual world expressing itself in the limited vocabulary of the physical, natural world. And what nuclear reactors, particle accelerators, and the Hubble telescope are for us, the medieval cathedral—and the cosmological “model” it represented—was for the medieval period: a kind of “experiment” that made visible an elusive and deeper truth. It is this iconic vision of the medieval cosmos that Lewis tried to get his students and audiences to see, and feel, and breathe. Thus the Oxford professor’s interest in medieval cosmology was not merely an arcane, archaeological antiquarianism. Why? Because being able to see the world with medieval eyes could provide even modern people with a “model” for thinking about the relationship between the natural and spiritual world.