Anima, according to Carl Jung, is the feminine side of a man's personal unconscious. It can be identified as all the unconscious feminine psychological qualities that a man possesses. In a film interview, Jung was not clear if the anima/animus archetype was totally unconscious, calling it "a little bit conscious" and unconscious. In the interview he gave an example of a man who falls head over heels in love, then later in life regrets his blind choice as he finds that he has married his own anima, the unconscious idea of the feminine in his mind, rather than the woman herself. The anima is usually an aggregate of a man's mother but may also incorporate aspects of sisters, aunts, and teachers.

Jung also believed that every woman has an analogous animus within her psyche, this being a set of unconscious masculine attributes and potentials. He viewed the animus as being more complex than the anima, as women have a host of animus images while the male anima consists only of one dominant image. Jung viewed the anima/animus process as being one of the sources of creative ability.

The anima is one of the most significant autonomous complexes of all. It manifests itself by appearing as figures in dreams as well as by influencing a man's interactions with women and his attitudes toward them. Jung said that confronting one's shadow is an apprentice-piece while confronting one's anima is the masterpiece. He also had a four-fold theory on the anima's typical development, beginning with its projection onto the mother in infancy, continuing through its projection on prospective sexual partners and the development of lasting relationships, and concluding with a phase he termed Sophia, doubtlessly in a Gnostic reference. It is worth noting that Jung applies similar four-fold structures in many of his theories.