Unfortunately the factual basis for Blavatsky's book is nonexistent. She claimed to have received her information during trances in which the Masters of Mahatmas of Tibet communicated with her and allowed her to read from the ancient "Book of Dzyan". The "Book of Dzyan" was supposedly composed in Atlantis using the lost language of Senzar but the difficulty is that no scholar of ancient languages in the 1880s or since has encountered the slightest passing reference to the "Book of Dzyan" or the Senzar language.