What was the title of C.S. Lewis's 1943 book arguing against the idea that nature alone explains morality?

The Abolition of Man is C.S. Lewis’s 1943 book arguing that moral values cannot be reduced to mere subjective feelings or explained away as products of nature alone. It grew from three lectures delivered at the University of Durham.

Lewis criticizes an unnamed educational text, which he calls The Green Book, for presenting value judgments as if they were only personal responses. He defends what he calls the Tao, a term he uses for a broad tradition of objective moral principles found across cultures.

The book is not primarily a political manifesto or a work of fiction. It is a compact work of moral philosophy and education, concerned with how schooling shapes the human character. Its final section warns that technological power without moral wisdom could produce a diminished humanity.

The title refers to the possibility that humanity could abolish itself by trying to remake human nature through unchecked scientific or technological control. Lewis’s argument is often discussed alongside his other apologetic works, but its focus is especially ethical and educational.