Which C.S. Lewis book argues that traditional moral values need to be preserved?

The Abolition of Man argues that traditional moral values need to be preserved.

C.S. Lewis published The Abolition of Man in 1943. The short work developed from three lectures delivered at the University of Durham in February 1943, later printed under the subtitle Reflections on Education with Special Reference to the Teaching of English in the Upper Forms of Schools.

Lewis criticized an approach to education that treated value judgments as merely subjective emotional reactions. He defended what he called the Tao, a term for a universal or traditional framework of objective moral principles shared across cultures.

The book is not a novel and does not directly present the fictional world of Narnia. Its final chapter warns that attempts to reshape humanity through technological control could ultimately destroy the very human nature such projects claim to improve.