The pregnant figure shows the involvement of the unconscious in the process, but also a conscious understanding is essential. Here, I think an approach to the conscious understanding of the integration of instinct is being portrayed. The man, who happens to be a Jungian analyst, would stand for Jung's approach to the problem. We see a vessel that seems to contain the universe. The sun and moon are under the hands of the Jungian/minister. The gem of the Midnight Jeweller is between them. The upward reaching hand is that of the bonobo (see detail), an ape that is considered our nearest genetic relative in the animal world.
The ape seems to be a reference to a historical symbolic figure called the Anthropos. He is the primordial man who represents the totality or wholeness for which we are striving, in him our higher and lower natures are unified. When his animal nature is emphasized, as here by the bonobo, it points to the fact that he also symbolizes the world of drives and instincts within us. In him our higher and lower natures are unified and the original pattern of functioning is reestablished. These two natures are represented by the opposites, the sun and the moon. In alchemy, the union of the sun and moon gives rise to the lapis or stone, which here is represented by the diamond. It seems the ape is being persuaded to touch the diamond, that is, the lower nature is being invited to participate in the quest for wholeness.
The action takes place in a vessel below a ruined castle which I think provides the key to an approach to the problem. The ruined castle is an alchemical symbol and represents a former attitude of consciousness, a person's present value system, in the process of collapsing. Life cannot be lived in the old way anymore so a new "home" must be built. This activates a process below, in the vessel. The vessel has many symbolic expressions. One example is the Celtic Cauldron of the Dagda, a precursor of the Grail and the atmosphere does appear Celtic. Another example comes from the Gnostic alchemist Zosimos who had a vision in which he saw a cosmic altar in the form of a bowl. (This ancient form is thought to be one of the original ideas behind the Holy Grail.) Here the initiate acquires nous. Nous is the light or wisdom of nature that we spoke of before; it is Sophia. So in this bowl an increase in consciousness occurs through a spiritual rebirth or renewal accomplished by attending to the instinctual aspects of life.