The terms occult and occultism (from the Latin term occultus "clandestine, hidden, secret") refer to belief in or study of supernatural claimed powers, often of a kind not approved of by established religion.
A vast array of currents in the Western esoteric tradition include occultism. Occultism became more influential in the Christian world during the 15th century, in association with the Renaissance and influence from various eastern occultist varieties, such as alchemy, Gnosticism, neo-Platonism, Hermeticism and Jewish Kabbalah.
One reason for the appeal of various esoteric organizations is the promise of occult and/or mystical knowledge, often in conflict with established religious authorities. Such organizations may attract anti-establishment individuals or individuals excluded from established society (such as Jews) and may become also politically anti-establishment.