Regardless of what the article posits, the movie was based on actual secret societies. I'm pretty sure Kubrick was trying to tell us something.
Anthony Frewin (assistant to Stanley Kubrick):
I had a friend who lived in the south of France, G. Legman. He supplied us with a lot of information about secret societies and sexual mores in Vienna at the time of Schnitzler. He also sent over a lot of illustrations of secret-society rituals and the Black Mass, mainly from the 19th century. We had a lot of illustrations, contemporary and even much older, of some ceremonies.
Anthony Frewin (assistant to Stanley Kubrick):
I had a friend who lived in the south of France, G. Legman. He supplied us with a lot of information about secret societies and sexual mores in Vienna at the time of Schnitzler. He also sent over a lot of illustrations of secret-society rituals and the Black Mass, mainly from the 19th century. We had a lot of illustrations, contemporary and even much older, of some ceremonies.