Sexuality is of the greatest importance as the expression of the chthonic spirit. That spirit is the ‘other face of God,’ the dark side of the God-image. The question of the chthonic spirit has occupied me ever since I began to delve into the world of alchemy.
Jung establishes the chthonic spirit as the theological and psychological ground of sexuality, identifying it as the dark aspect of the divine image and the central preoccupation motivating his alchemical investigations.
, Memories, Dreams, Reflections, 1963thesis