To Robert Eisler
Dear Dr. Eisler, 25 June 1946
What I said in Two Essays about archetypes in the animal psyche was only an aside.
I hazard the conjecture, which is based .on certain experiences, that the lowest layers of our psyche still have an animal character.
Hence it is highly probable that animals have similar or even the same archetypes.
That they do have archetypes is certain in so far as the animal-plant symbioses clearly demonstrate that there must be an inherited image in the animal which drives it to specific instinctive actions.
I have dealt with this point only in one essay: “Instinct and the Unconscious” (in Contributions to Analytical Psychology, Kegan Paul, London, 1928).
An offprint of my lecture “Archetypes of the Collective Unconscious” follows by the same post.
I have also asked my publisher to send you a copy of my Psychology and Alchemy, which of all my writings is probably the most concerned with archetypes.
C.G. Jung ~Carl Jung, Letters Vol. 1, Page 427-428.