But why is it the mouse, of all animals, that is the medium of the development?
We cannot give any compelling reasons for this, but Mrs. Brunner has given you enough evidence that the mouse is a soul animal.
She has also quite correctly pointed to the transparency of the mouse and interpreted it as spirituality.
Transparency is a criterion for the spirituality of matter.
So the lapis philosophorum is also called vitrum (glass), precisely because it is of a spiritual nature, or lapis aethereus.
So we have to imagine that the mouse, by virtue of its transparency, can form the spiritual vessel, in which the various transformations from animal to man take place.
The starting point of this development is the gray mouse.
The gray mouse is, as Mrs. Brunner has mentioned, an animal that stands in connection to the darkness of the soul; it represents that fleetingly glimpsed, dark nature
of man that makes itself unpleasantly felt from time to time, above all at night.
Mice are also allegories of gnawing thoughts, therefore, of pricks of conscience, that haunt us like spirits at night.
These are chthonic animals with a certain relation to death.
As deathly animals, they are brought in connection with Apollo.
The Greeks worshipped Phoebus Smintheus, that is, the Mouse-Apollo, in whose temple mice were kept under the altar.
There they were looked after and cared for, and in a way this had the meaning of apotropaic magic.
We might ask what, for heaven’s sake, Apollo, the sun god, should have to do with mice.
Now we know that Apollo is not only the god of light, but also the bearer of death, because his arrows can bring the plague, which is an illness that is spread by animals such as mice and rats.
The mouse in general is an uncanny, deathly messenger.
A great mouse plague is an evil omen for a country.
This is understandable, because there were times when veritable mice epidemics broke out, when they multiplied in great numbers, destroyed all the crops, and
caused famine and illness.
Participant: In Faust the mice also appear as spirits.
Professor Jung: Where?
Participant: When the pentagram prevents the devil from crossing the threshold.
Professor Jung: Yes, there Mephistopheles calls his assistants, the rats and the mice, that they should gnaw through the pentagram:
“The Lord of Rats and Mice,
Of Flies, Frogs, Bugs, and Lice,
Summons you to venture here,
And gnaw the threshold here.”
Participant: The gray color of the mouse is also the color of the spirits.
Professor Jung: Yes, it is the color of darkness and of the spirits.
So, you see, for all these reasons we may understand the mouse as a dark and enigmatic starting point of the development.
In Greek antiquity, for example, the mice that crept out of graves were considered the spirits of the dead, and were, therefore, taken care of and fed. ~Carl Jung, The Children’s Seminar, Pages 363-364.
Image: The Bronze Mouse of Apollo Smintheus