Seegee Jhung was a remote Terran ancestor. He outlined a theory which explained the anima and prophesied the theory of the Archetypes: the Mother, the Hetaira (such as Gamont), the Amazon (such as Fish Speakers) and the Medium (such as Reverend Mothers).
According to the BG digma, Archetypes were public relations illusions used to manipulate the gullible.
Ghanima Atreides studied the roots of her own name intrigued by the anima aspect and set about a systematic exploration of her ancestral memories. As a result she learned about Jhung's theory.