The Better Angels of Our Nature: Why Violence Has Declined by Stephen Pinker
Details
This book is priceless, but loooong! It's too big for me to summarize, so I have borrowed the summary of it from The Book Reporter and had to summarize that.
Actually the book is much more fun to read than than the summary.
The original summary (100 pages) is posted in the More > Files section above
ALONG WITH MY SUMMARY (15 pages) OF My Summary (30 pages) of the summary (100 pages.)