Description:This is a good review of a limited set of perspectives on what many call Sacred Fire. I feel the author's experience was perhaps too limited in perspective. Much of the focus is on information coming from the Middle East and Western Asia. That isn't a negative though, just something to be aware of. This is a very broad topic and I think a modern review of it would necessitate more information from Africa, Australia, and the Americas.
Sometimes these "white bound" gnostic books can be hard to read and excessively wordy. Part of that being due to the expectations of the place and time the author is coming from. This work stretches in that direction at times, but is not hard to comprehend.
This is a good starting place for people interested in Sacred/Secret Fire, especially if your background includes a lot of familiarity with Judeo-Christrian origins.