The book taps to the very fundamental essence of human nature and what constitute the evolutionary biological dictates of life itself; life as a function encapsulating meaning and purpose and a construct that develops - as whole - across time. Carnegie maps the psychological glue that glues humans together for a maximum positive collective growth. I believe that this book is a master piece that comes second in the line of the most important books ever written in human history: Second after the bible, of couse.