This is an interesting 'big picture' survey of the methods we use to derive values. I thought the beginning -- the description of the 'Six Ways' was completely fascinating. The way gets a little muddier when the author tries to show how the six methods blend together to form many other variations. But if you generally like philosophy, you'll probably be able to go farther down the path than I could.
This is a book that will make you think, and give you an analytic tool for future thinking.