I’ve always found these guys fascinating, but there’s so much writing about them out there, and so much of it is dominated by tinfoil hatters and other new age weirdos that it’s really hard to sift through all the muck and find some good reading.
Here’s what I want: books to cover the gamut of Occult/Magick/Theosophy/Hermeticism/Gnosticism/Alchemical thought/etc. thinkers and practicioners that are as objective, rational, historical, and clear-headed as possible. John Dee, Aleister Crowley, Jack Parsons, Helena Blavatsky, Robert Fludd, and so on - if it’s interesting and weird, I want to read it!
I don’t need them to be completely rational or objective - I’d probably enjoy reading writing about Magick or Gnosticism (and their practicioners) by someone who’s personally invested in that world - but I want to steer away from people working a personal agenda or people that are just-plain off the rails. In other words, I really want to read about the weird theories connecting Jack Parsons’ “Babylon Working” experiments to the first appearance of UFO’s, but I don’t want a book that then tries to connect that to 9/11, Michael Jackson, and the Illuminati, if you catch my drift.
I’d definitely be open to some sort of reader, compendium, or anthology that brings a bunch of this stuff together in one place, if such a thing exists.
I don’t know how much of a scholar he is, but Nicholas Goodrick-Clarke wrote a rarher interesting book called “The Occult Roots of Nazism”. It uses a lot of citiations from what look to be primary sources, and the book did a good job of not setting off my BS detector. In fact, in the later chapters he goes out of his way to disprove the whole “Hitler and the Spear of Destiny” legend that’s so popular.(I hate the Spear of Destiny. It’s such a fricken cliche for occult fiction).
John Carter, Sex and Rockets: The Occult World of Jack Parsons.
Michael Howard, The Occult Conspiracy.
James Webb, The Occult Underground and The Occult Establishment.
Robert Anton Wilson, Cosmic Trigger.
Frances Yates, The Rosicrucian Enlightenment. (Also see The Rosicrucian Enlightenment Revisited, ed. by Ralph White. Sort of a Yates Festschrift.)
I’m not sure if this is exactly what you’re looking for or not, but several of Martin Gardner’s books (like this one or this one) describe weirdos, quacks, and pseudoscientific theories.
It’s not quite the truly detailed picking apart of her myths about herself that someone ought to try to write, but Peter Washington’s Madame Blavatsky’s Baboon at least usefully fills the niche of being a popular history of Theosophy that doesn’t take those claims at face value.
Spirits, Stars and Spells: The Profits and Perils of Magic, by L. Sprague de Camp, is just exactly what the OP is looking for. Erudite, entertaining, literate, and in no way credulous. Read all about Helena Blavatsky, the medieval alchemists and astrologers, the crimes of Gilles de Rais and Elizabeth Bathory, etc., etc.
For a good fictional treatment, try Robert Anton Wilson’s “Historical Illuminatus” novels – The Earth Will Shake, The Widow’s Son, and Nature’s God. Casanova and Count Cagliostro play minor roles, and there’s a lot about Rosicrucianism and Freemasonry. Also, try Masks of the Illuminati, which features Aleister Crowley as a central character.
Speaking of Crowley – Avram Davidson’s collection of essays, Adventures in Unhistory, includes an utterly delicious (in prose style) account of his life.