Psyche and Matter by Marie-Louise von Franz

selected passages:

“Matter and Psyche from the Point of View of the Psychology of C.G. Jung” (1974)

“There are probably many different numerical structures that repeatedly make a parallel appearance in the psychic and physical realms. … This is … where further research must be encouraged. When Jung came to this point, he said the following: ‘Now I have the feeling that I’ve hit my head against the ceiling. I can’t get any farther than this.’ This was shortly before his death. Now, I have not tried to produce any creative new ideas, but rather, in my book Number and Time I have tried to take this idea that Jung hinted at somewhat further and to show that the natural numbers in fact do possess in exactly the same way in the world of psychic representations
all the qualities that they possess mathematically and that they have in physics and in the hereditary code. Thus a real, absolute isomorphism is present. I was able to take this up to the number four. Then it became too complicated, and at that point I also hit my head on the ceiling.” Page 37

“Symbols of the Unus Mundus” (1968):

“When he created the concept of synchronicity, Jung laid a foundation which might lead us to see the complementary realms of psyche and matter as one reality. … Synchronistic events … seem to point towards a unitary aspect of existence which transcends our conscious grasp and which Jung has called the unus mundus.” 40
The “mandala is the psychological equivalent and synchronicity the parapsychological equivalent of the unus mundus.” Page 41

“The above-mentioned mandalas [in the writings of Marsilio Ficino, Pico della Mirandola, Giordano Bruno, Ramon Lull] are attempts to combine the psychic equivalent of the unus mundus (i.e., mandala) with an attempt to tap the ‘absolute knowledge’ (i.e., synchronicity). Some of them are triadic, and these seem more explicitly intended to put the inner man in order, whereas others can be turned, and these have the additional purpose of obtaining ESP knowledge or of producing
magical effects. Some of these cosmic models, such as the calendar of Guillaume de Digulleville, which describes in Psychology and Religion and Psychology and Alchemy, have a double structure of two circles. The same holds true for the mysterious modern vision of a world clock which Jung published in Psychology and Alchemy. Jung suggests that this world clock might represent the essence of the time-space union or rather its origin … .” Page 44

“This complementary double aspect of number (quantity and quality) is in my opinion the thing which makes is possible for the world of quantity (matter) and of quality (psyche) to interlock with each other in a periodical manner (world clock!).” Page 57

http://www.jgsparks.net/guides/vF/Psyche&Matter.pdf

Image: From Herbert van Erkelens, Wolfgang Pauli und der Geist der Materie, p. 214. See also C.G. Jung, Psychology and Alchemy, pars. 307ff. and Psychology and Religion, “Psychology and Religion,” pars. 112ff.