BACKGROUND INFORMATION ABOUT MYSTERIUM CONJUNCTIONIS
All of the alchemical texts that Jung discusses were written by Christian authors. The authors thought that they were writing treatises in alchemy, not treatises in modern chemistry.
To many people, their terminology and imagery sound a bit fanciful, to say the least. But Jung interprets their terminology and imagery as expressing certain kinds of information about their unconscious processes as each alchemist proceeded to work on his opus. Oftentimes, the alchemists conceived of their work on the opus as designed to produce gold. However, no alchemist is known to have claimed that he had succeeded in producing the gold. But this did not stop one alchemist after another from writing treatises about the work on the opus.
I will not say that alchemical treatises were ever as common as self-help books in psychology are today. However, over the centuries numerous Christian authors wrote alchemical treatises. Apparently all of the Christian alchemists were men. In any event all of the alchemists that Jung studied were men.
By way of a brief overview, the alchemists referred to certain stages in the process involved in producing gold: (1) the unio naturalis is the starting point; (2) the unio mentalis comes next; and (3) the culminating stage is the unio mundus (also known as the unio mystica).
(1) In terms of the psychological equivalents, Jung sees the unio naturalis (page 488) as referring to the human condition.
(2) Jung sees the equivalent to the unio mentalis as the psycho-spiritual efforts many Christians made to control and moderate their concupiscible and irascible appetites and tendencies (page 143-144).
(3) Jung sees the equivalent to the unio mystica (a.k.a. the unio mundus) as the personal transformation involved in deep mystical experiences. Jung mentions in passing three stages involved in the emergence of the unio mystica: (1) emundatio (purification), (2) illuminatio, (3) perfectio (page 451).
However, Jung focuses his attention primarily on the unio mentalis. In part, his focus reflects the focus he finds in the alchemical texts. In part, his focus on the unio mentalis reflects the applications and parallels and analogies between the alchemical processes and the psychological processes involved in the process of personal individuation.
THE GOSPEL ACCORDING TO JUNG
Jung rarely expresses himself succinctly. But I will try here to explain succinctly certain key points in his thought. I will number them in an order that I have constructed. I wish I could have formulated a new Ten Commandments according to Jung. Instead, I have formulated the following 17 points points.
(1) Jung sees the human condition in modern Western culture today as being characterized by the divided self. As I explained above, in alchemical terminology, the human condition is the unio naturalis.