The coniunctio affords another example of the gradual development of an idea in the course of the millennia. Its history flows in two main streams which are largely independent of one another: theology and alchemy. While alchemy has, except for a few traces, been extinct for some two hundred years, theology has put forth a new blossom in the dogma of the Assumption, from which it is evident that the stream of development has by no means come to a standstill. But the differentiation of the two streams has not yet passed beyond the framework of the archetypal hierosgamos, for the coniunctio is still represented as a Jungian of mother and son or of a brother-sister pair. Already in the sixteenth century, however, Gerard Dorn had recognized the psychological aspect of the chymical marriage and clearly understood it as what we today would call the individuation process. This is a step beyond the bounds which were set to the coniunctio, both in ecclesiastical doctrine and in alchemy, by its archetypal symbolism.
— Carl Gustav Jung
Two streams run through Western spiritual history — theology and alchemy — and Jung's point is that neither has managed to think beyond the image they started with. The hierosgamos, the sacred marriage, keeps organizing the material: mother and son, brother and sister, the feminine absorbing the masculine or surrendering to it. Two millennia of elaboration, and the template holds. That is not a failure of intelligence; it is a disclosure about how archetypal forms work. They generate endless variation and resist genuine transformation.
What Dorn saw in the sixteenth century is the crack in this pattern. He understood the chymical marriage as something happening inside a person, not between cosmic powers or ecclesiastical symbols. That move — inward, psychological, away from projection onto heaven or matter — is the step Jung names as genuinely new. And yet the dogma of the Assumption, which Jung reads almost approvingly as theology still alive, recloths the same hierosgamos in new vestments. The psyche is still reaching upward, still staging its wholeness as a celestial event rather than an interior one.
The question the passage leaves open is whether the inward turn Dorn began has actually landed anywhere, or whether individuation has simply become the new name for the same ascent — the sacred marriage relocated to the self, the symbolic furniture rearranged, the structure unchanged.
Carl Gustav Jung·Mysterium Coniunctionis: An Inquiry into the Separation and Synthesis of Psychic Opposites in Alchemy·1955