The Secret Wisdom of the Qabalah by J.F.C. Fuller
Background Information: The Publisher, The Yogi Publication Society is a press started by William Walker Atkinson at the turn of the 20tdh century to promote his writings on "New Thought," which was the New Age movement of the time. Atkinson himself was quite a character. He was a prolific writer, with over 150 books to his credit, often under any of several pen names. He rose to prominence at the beginning of the 20th century, but seems to have become forgotten in the following decades, though he and the Yogi Publication books are experiencing a new renaissance at the beginning of the 21 century.
Many of the books were written by Atkinson, but they also published other prominent metaphysical works by other authors. The company has changed hands a number of times, so many that the original history was lost to the current owners, but the books are still in print, and still inspiring spiritual seekers.
Before I can even touch on the content of the book, it's necessary to talk about the author. There are some people and events in history that are just so peculiar, so unlikely, that they test the bounds of believably. Such is the case of JFC "Boney" Fuller, the author of this work. I've got more in-depth links below, but in a nutshell, Fuller's greatest fame is as the father of modern tank warfare. He literally wrote the book on tank strategy (actually several), and much of it is still used today. He had mostly retired from military work after WW1, but was still influential as the tank became a dominant weapon in the theater of war. Despite being British, he was an ardent Fascist and a friend of Adolph Hitler. He was invited to Der Fuhrer's 50th birthday, and upon observing the rank upon rank of tanks and mechanized infantry passing, Hitler asked "How do you like your children?" Fuller responded, "They've grown so fast I hardly recognize them!"
Fuller has been given credit for Blitzkreig warfare. This is the wacky part: Fuller based his concepts of tank warfare on concepts taken from the Kaballah. Life is stranger than you can imagine. Despite being a fascist and Nazi sympathizer he was also an enthusiastic devotee of the ancient Jewish mystical tradition. Go figure.
https://www.historynet.com/jfc-boney-fuller-wacko-genius-of-armored-warfare.htm
https://en.wikipedia.org/wiki/J._F._C._Fuller
As for the book itself, I must preface by saying I know very little about this subject, so I can't discuss it from a critical point of view. The book itself sticks to it's topic, and introduces a lot of interesting concepts. We've probably all seen the Kaballah diagram, with it's 3 pillars and 10 particular "sephiroth," and this book does a nice job of explaining them and also reconciling it with modern relatable concepts, as well as religious concepts. The Author describes how all of this represents the evolution of things through three levels from inspiration and concept to it's physical incarnation, but also the changes that a thing can go through during that evolution, and that's what the Kaballah tries to map out. The value of that seems apparent.
Like a lot of people, I'm actually more familiar with the Taoist concept of Yin and Yang, and if you are too, you'll appreciate a lot of similarities. Both systems attempt to create a model inclusive of everything, in such a way as to find a repeatable, accessible, scientific pattern. You'll find a cyclical evolution across two opposite poles (yin/yang in Taoism, Severity/Mercy in Kaballah). While the names in Kaballah may sound more judgemental, they actually represent non-judgemental polar opposites the way yin and yang do. In a way, Kaballah is like Taoism turned 90 degrees, and offers valuable perspectives. As with Taoism, this is a a way of looking at things that one would have to put on for a while like a glasses and endeavor to see the world through if one wants to understand it completely.