Which C.S. Lewis book argues that human nature is being weakened by technological power?

The C.S. Lewis book arguing that human nature is being weakened by technological power is The Abolition of Man. It was published in 1943 and developed from three lectures delivered at the University of Durham.

Lewis criticizes an approach to education that treats moral values as merely subjective emotions. He argues that societies depend on an objective moral order, which he calls the Tao, and warns that technological control over nature can become control over human beings.

The book is philosophical rather than fictional, and its title refers to the possible transformation or loss of humanity, not to a literal disappearance of the species. It is frequently discussed alongside Lewis’s wider concerns about education, moral realism, scientific power, and the limits of social engineering.