What was C.S. Lewis’s 1943 book of Christian philosophy about the dangers of rejecting objective values?

C.S. Lewis’s 1943 book about rejecting objective values is The Abolition of Man.

The Abolition of Man developed from three lectures Lewis delivered at the University of Durham in February 1943. The book criticizes an approach to education that, in his view, treats moral judgments as merely subjective emotional reactions. Lewis argues that human societies depend on shared principles of value and moral formation.

A central concept is the Tao, Lewis’s name for a cross-cultural body of basic moral principles. He contends that attempts to reshape humanity through purely technological power could ultimately undermine the human qualities that make moral judgment possible.

The work is philosophical rather than a conventional novel or devotional guide. It is often discussed alongside Lewis’s Christian apologetic writing, but its argument draws on moral traditions from several civilizations. Its three chapters are followed by an appendix listing examples of traditional moral principles.