system
A chat on 4chan
human
I find Blavatskies views on lost civilizations and the solar system fascinating. Is there something to Theosophy or was it just another Luciferean Masonic spook?
gpt
H.P.B. (from what i understand) traveled most of her life to the locations where ancient texts, traditions and other forms of knowledge are / were found. 

Her broad study of this knowledge allowed her document the correlations, similarities and differences between the various sources of knowledge and wisdom. This in its essence is what Theosophy is.

it is hard to find a different reference that comes close to her work. the secret doctrine is one anon would highly recommend for the reasons stated above.