The history of popular occultism studies how occult ideas and practices, tarot reading, popular astrology, spiritualism, mail order correspondence courses and mass market grimoires, spread among a general readership through cheap print and popular societies, distinct from the history of elite esoteric philosophy transmitted among trained initiates. Scholars of Western esotericism turned to this material seriously from the 1970s, treating the nineteenth and twentieth century occult revival's popular publishing, from Spiritualist newspapers to Golden Dawn offshoots sold by mail, as historical evidence in its own right rather than as a debased footnote to more respectable esoteric philosophy.
Much of what a general reader today associates with the occult, popular tarot decks, newspaper horoscope columns, correspondence course initiations, descends from this specifically popular and commercial nineteenth and twentieth century print culture rather than from any older continuous esoteric lineage. The atlas relies on the discipline to date accurately when a widely practiced modern occult system actually originated, frequently a nineteenth or twentieth century commercial innovation, rather than accepting a system's own marketing claim to ancient or unbroken descent.