Helena Blavatsky
1888
The Secret Doctrine is a seminal text in the development of fringe history, bringing together elements as disparate as the search for Atlantis and Lemuria, hyperdiffusionism, Eastern mysticism, and space aliens. It is the crossroads for so many fringe beliefs that it is hard to overestimate its importance. The text appears here as transcribed by Project Gutenberg, in two volumes corresponding to the two original volumes of the 1888 edition.