C. S. Lewis on the Flat Earth

I recently learned of his final book, The Discarded Image: An Introduction to Medieval and Renaissance Literature, published posthumously in 1964. I ordered a reprint of this book because I understood that it also discussed medieval cosmology. This is of interest to me because flat-earthers hang on to what I call “the Columbus mythology”: that nearly everyone in the West thought that the earth was flat until five centuries ago.

The topic of Chapter V of The Discarded Image was the universe, which, no surprise to me, was Ptolemaic through the eyes of Christianity. This chapter only peripherally mentioned the earth being spherical. But given the series of concentric spheres that moved around the earth, a flat earth makes no sense in that it would have broken the symmetry of the cosmology. Furthermore, I don’t think any flat-earthers today believe in the celestial sphere or spheres. Rather, modern flat-earthers believe that there is a dome over a flat earth, not a sphere around a flat earth.

Lest anyone construe the silence about the earth’s shape in Chapter V of The Discarded Image as support for flat earth, Chapter VII, which is about the earth, removes any doubt. Chapter VII also indicates that Lewis was aware of the rise of the modern flat-earth movement in the nineteenth century. For instance, this is found on page 140:

Physically considered, the Earth is a globe; all the authors of the high Middle Ages are agreed on this. In the earlier ‘Dark’ Ages, as indeed in the nineteenth century, we can find Flat-earthers. Lecky, whose purpose demanded some denigration of the past, has gleefully dug out of the sixth century Cosmas Indicopleustes who believed the Earth to be a flat parallelogram.

And this is found on page 141:

The implications of a spherical Earth were fully grasped. What we call gravitation—for the medievals ‘kindly enclyning’—was a matter of common knowledge. Vincent of Beauvais expounds it by asking what would happen if there were a hole bored through the globe of Earth so that there was a free passage from the one sky to the other, and someone dropped a stone down it. He answers that it would come to rest at the centre.

It seems that modern flat-earthers have regressed from the Middle Ages, thinking that the earth is flat and that there is no such thing as gravity.

Indeed, this question about a tunnel through the earth is a classic problem that some physics textbooks include in their discussions of Newtonian gravity. Ignoring wind resistance, the dropped stone will oscillate from one side of the earth to the other within a period of a little less than 90 minutes. When wind resistance is included, the stone will eventually come to rest at the earth’s center.

Lewis went on to discuss what he thought were two reasons why people so readily think medieval cosmology was based upon a flat earth.

It seems that modern flat-earthers have regressed from the Middle Ages, thinking that the earth is flat and that there is no such thing as gravity.