Whereas the personal unconscious consists for the most part of complexes, the content of the collective unconscious is made up essentially of archetypes.
Collected Works 9.1 ¶ 88
The concept of the archetype, which is an indispensable correlate of the idea of the collective unconscious, indicates the existence of definite forms in the psyche which seem to be present always and everywhere.
Mythological research calls them “motifs.”
In the field of comparative religion they have been defined by Hubert and Mauss as “categories of the imagination.”
Adolf Bastian long ago called them “elementary” or “primordial thoughts.”
From these references it should be clear enough that my idea of the archetype–literally a pre-existent form–does not stand alone but is something that is recognized and named in other fields of knowledge.
Collected Works 9.1 ¶ 89
Psychic existence can be recognized only by the presence of contents that are capable of consciousness. We can therefore speak of an unconscious only in so far as we are able to demonstrate its contents. The contents of the personal unconscious are chiefly the feeling-toned complexes, as they are called; they constitute the personal and private side of psychic life. The contents of the collective unconscious, on the other hand, are known as archetypes.
Collected Works 9.1 ¶ 4
Again and again I encounter the mistaken notion that an archetype is determined in regard to its content, in other words that it is a kind of unconscious idea (if such an expression be admissible):
It is necessary to point out once more that archetypes are not determined as regards their content, but only as regards their form and then only to a very limited degree.
A primordial image is determined as to its content only when it has become conscious and is therefore filled out with the material of conscious experience.
Its form, however, as I have explained elsewhere, might perhaps be compared to the axial system of a crystal, which, as it were, preforms the crystalline structure in the mother liquid, although it has no material existence of its own. This first appears according to the specific way in which the ions and molecules aggregate.
The archetype in itself is empty and purely formal, nothing but a facultas praeformandi, a possibility of representation which is given a priori.
The representations themselves are not inherited, only the forms, and in that respect they correspond in every way to the instincts, which are also determined in form only.
Collected Works 9.1 ¶ 155