Coniunctio represents the alchemical and depth psychological concept of sacred union, where opposing or complementary principles merge to generate transformed consciousness and wholeness beyond their separate natures. The Latin term meaning “conjunction” or “joining together” originates in medieval alchemy’s opus magnum, where the marriage of Sol and Luna (sun and moon, sulphur and mercury, king and queen) produces the Philosopher’s Stone - not literal gold but spiritual transformation. Carl Jung recognized coniunctio as central archetype of individuation, the psyche’s drive toward integration where conscious and unconscious, masculine and feminine, spirit and matter unite not through one dominating the other but through genuine synthesis that preserves difference within unity.
The coniunctio differs crucially from mere fusion or collapse into undifferentiation - what Jung termed participation mystique or inflation. True conjunction requires prior separation and differentiation (separatio), the painful recognition of opposition, before conscious reconciliation becomes possible. In psychological terms, this might manifest as integration of shadow material, reconciliation of persona with inner reality, or what Jung called the mysterium coniunctionis between ego and Self. The alchemists depicted this process through striking imagery: the royal couple in coitus within a bath, the hermaphrodite or rebis (literally “double thing”), dragons devouring each other, suggesting both erotic union and mutual transformation through encounter with radical otherness.
The concept intersects with non-duality while maintaining differentiated awareness, Participatory knowing as union of knower and known, the coincidentia oppositorum (coincidence of opposites) in mystical traditions, and Hegel’s dialectical synthesis. It connects to sacred marriage (hieros gamos) in religious symbolism, emergence of novel properties from integration, tantra’s union of wisdom and compassion, and discussions of how psyche generates wholeness from fragmentation. Coniunctio points toward integration as ongoing creative process rather than static achievement - a dynamic equilibrium perpetually renewed through conscious relationship between previously sundered aspects of being.