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
Jung defines the decisive distinction between the archetype-as-form and archetypal contents, arguing that content arises only through the infilling of conscious and cultural experience upon a purely formal matrix.
, The Archetypes and the Collective Unconscious, 1959thesis