My sister turned me on to the Enneagram back in the late '80s before it had become so kool and trendy. Don't be misled by the lack of cover art or excerpts here...this was one of the first books written on the subject, and it's still one of the best. As the other reviewer noted, the "self-test" is one of the clearest and most concise and the emphasis in the book is on your fatal flaws or "sin-types" as the Catholic authors dub them. Rather than allowing you to wallow in self-congratulatory insight of some other books (and similar self-analytic tools, like horoscopes etc.), this book takes a direct approach to telling you why you are so screwed up - because of your type! It has a distinct Christian/catholic approach, including a chapter on how Jesus embodies all 9 types. So this is not the book to read if you couldn't care less about the spiritual implications of your personality. If you're a Christian, it is DEFINITELY the definitive work to own. Having read Palmer, Riso and all the other "experts", I still come back to this one, and I've personally ordered my third copy.