The author has something unique in his book, he doesn't hesitate to say "I am not sure" when he isn't (something rarely found in most books today). Mr Barrett did a very scholarly book, which has plenty of details and doesn't hesitate to show that some of the ealier "experts" were not really experts at all but were more flamboyant than knowledgeable. If you want to know verifyable facts about freemasonry, Rosicrucianism and other secret societies, this is a good book to start with (alhtough not an end all book on the subject). One of my few criticism is that some groups like Martinism and Melanchthonism have been left out of the book... A worthwhile read!
I was doing research into conspiracy theories and secret societies when I happened upon this book. Looking back I'm glad I found this book first, before I went on some wild goose chase following unsubstantied rumors and sinister allegations. The author is obviously very learned in this area and while I haven't read them I would also suggest his other books that have to do with religions and occult societies as well. The author doesn't indulge in some of the more preposterous accusations against the Masons, the Rosicurians, and the Illumanti, but instead presents the history and the teachings of these orders in a straightforward and informative manner.