Western esotericism — encompassing Hermeticism, Kabbalah as received through Renaissance Europe, Rosicrucianism, Freemasonry, Theosophy, Anthroposophy, ceremonial magic, and contemporary Paganism — is a river of alternative spiritual knowledge that has flowed alongside and beneath mainstream European religion for two millennia. Its characteristic claim is that ordinary religious practice transmits the outer form of a teaching whose inner core can only be accessed through initiation, direct experience, and the cultivation of deeper faculties of perception. Far from being fringe curiosities, these traditions have profoundly influenced Western art, science, and philosophy — Kepler, Newton, Goethe, and Jung all moved in esoteric currents.
Rumi