Which 1943 book by C.S. Lewis developed ideas from his Riddell Memorial Lectures?

The Abolition of Man developed ideas C.S. Lewis presented in his 1943 Riddell Memorial Lectures.

The book consists of three chapters and addresses education, moral value, and the consequences of treating judgments of value as merely subjective feelings. Lewis argues for an objective moral order, which he calls the Tao in the work.

The opening chapter responds to a schoolbook passage that Lewis believed undermined objective value. The following chapters connect moral education with the future of humanity and with the possibility that technological power could diminish rather than improve human nature.

The Abolition of Man is not a novel and is separate from Lewis’s Narnia fiction. It is a compact work of philosophical and educational criticism, and scholars often read it alongside his other apologetic books, including Miracles and Mere Christianity.