Probably the third Webb book to pick up on post modern lhp theory and setian philosophy. (Uncle Set then Mysteries being the other two respectively). Has some additional rubric towards the end for invocation work. Magus Webb has a way of exposition that makes it conducive to a broad group of learning styles. His candor and erudition are top notch. This book is not for the armchair occultist, it forces you to participate if you are going to get anything out of it.