The occult, in the broadest sense, is a category of esoteric supernatural beliefs and practices which generally fall outside the scope of religion and science, encompassing phenomena involving otherworldly agency, such as magic and mysticism and their varied spells. It can also refer to supernatural ideas like extra-sensory perception and parapsychology.
Introduction by Manly P. Hall
The Secret Doctrine by Helena Blavatsky
The Rosicrucian Cosmo-Conception by Max Heindel