Interesting choice of Victorian occult fluffery. The author of the piece does describe it as fantasy, but it's responsible for a whole host of exciting real-world madness in the 20th century and afterwards.

It's important to recognise that until the internet made it much easier for people to discuss ideas and find counterarguments, there were large numbers of people floating around claiming that the contents of these books were not only beyond reproach, but that <insert group invented in the 20th century> was an unbroken descendant of one of the mythical groups invented by Victorian pseudohistorians.