The Abolition of Man, by C.S. Lewis

In these three brief essays, C.S. Lewis takes up the issue of moral relativism, how our view of what is considered rational and objectively true has narrowed significantly in modern times, and how that affects our outlook on morality, culture, art, etc.  He makes the point that children can be accustomed to this narrow view quite early in life before they can be aware of what is being done to them and the result is an adult with an impoverished moral imagination.