A really good book, but it asumes a certain amout of background knowledge on the part of the reader. It does, however provide sufficient information for the reader to gain some real insite into his/her personality, with a few basic calculations. You will need to refer back regularly and apply what has been learned to gain the full benefit from this book. I would have liked a more in-depth coverage of certain topics that I found particularly interesting, so as to aquire a more detailed understanding. A book well worth having if you read Keith Mason, David Tansley or Alice Bailey.