Which C.S. Lewis book argues that human beings have a moral law known as the Tao?

The C.S. Lewis book that discusses a universal moral law called the Tao is The Abolition of Man. It was published in 1943 and developed from three lectures Lewis delivered at the University of Durham in 1943.

Lewis uses “the Tao” as a broad term for traditional moral principles found across cultures and religions. His argument is that moral education cannot be reduced to producing feelings or preferences, because judgments about value depend on objective principles. The book criticizes an approach to education that treats emotional responses as the whole basis of value.

The Abolition of Man is a short work of philosophy and cultural criticism, not a Narnia novel or a conventional theology textbook. Its final section considers how technological power might be used to reshape humanity. The title refers to the possible loss of shared human values and moral agency, rather than to literal physical disappearance.