The Abolition of Man by C.S. Lewis
I took a long, long time to read this little book. It contains a lot of big ideas in a very small package, and I just read a bit here and a bit there and didn't hurry through it, although that would have been easy to do with such a small book (81 pages).
I am definitely on board with Lewis' basic premise here, which dovetails rather nicely with other reading I've done. His main theme is that there are absolutes--principles of right and wrong that exist in the world at large--which are not the product of human imagination or belief.
His contention is that by refusing to acknowledge that foundation of the universe, and attempting to use some other method of determining a correct course of action (most often guided by the latest "scientific advances" combined with the most current ideology), we destroy the very thing--mankind--we are attempting to "save."
Naturally, Lewis said it much more eloquently and persuasively than I do. Another interesting feature is the appendix which is a collection of "wisdom quotes" from various ages and cultures, which, although very different in origin, reflect the general absolutes which Lewis is defending.
This book was written during World War II, and although only the most oblique references are made to Nazi Germany, it is evident to me that at least part of the the message is directed at what was happening there. However, the message was intended to be timeless, not timely, and the need of the world to hear what Lewis has to say is perhaps even more desperate than it was then.