Which C.S. Lewis book was adapted from his lectures on medieval and Renaissance literature?

The C.S. Lewis book adapted from his lectures on medieval and Renaissance literature is The Discarded Image. Published in 1964, it presents the intellectual model of the universe that shaped much pre-modern European writing.

Lewis explains how medieval writers imagined a structured cosmos containing Earth, the planets, the fixed stars, and the heavenly realms. He calls this system the “medieval model,” emphasizing that literature cannot be fully understood without recognizing the world picture its authors inherited.

The book grew out of Lewis’s teaching and scholarly work at Oxford and Cambridge. It is not a fantasy novel and does not describe Lewis’s own fictional world of Narnia. Instead, it is a work of literary history and criticism aimed at readers who want to understand medieval imagination.

The title’s “discarded image” refers to the older cosmological picture that modern people largely replaced. Lewis argues that studying it helps readers see historical literature on its own terms rather than judging it only through modern assumptions.