Marie-Louise von Franz was a Swiss Jungian psychologist and scholar.

Von Franz worked with Carl Jung, whom she met in 1933 and knew until his death in 1961. Jung believed in the unity of the psychological and material worlds, i.e., they are one and the same, just different manifestations. He also believed that this concept of the unus mundus could be investigated through research on the archetypes of the natural numbers. Due to his age, he turned the problem over to von Franz. Two of her books, Number and Time and Psyche and Matter, deal with this research.

Von Franz, in 1968, was the first to publish that the mathematical structure of DNA is analogous to that of the I Ching. She cites the reference to the publication in an expanded essay "Symbols of the Unus Mundus," published in her book Psyche and Matter. In addition to her many books, Von Franz recorded a series of films in 1987 titled The Way of the Dream with her student Fraser Boa.

Von Franz founded the C.G. Jung Institute in Zurich. In The Way of the Dream she claims to have interpreted over 65,000 dreams. Von Franz also wrote over 20 volumes on Analytical psychology, most notably on fairy tales as they relate to Archetypal or Depth Psychology, most specifically by amplification of the themes and characters. She also wrote on subjects such as alchemy, discussed from the Jungian, psychological perspective, and active imagination, which could be described as conscious dreaming. In Man and His Symbols, von Franz described active imagination as follows: "Active imagination is a certain way of meditating imaginatively, by which one may deliberately enter into contact with the unconscious and make a conscious connection with psychic phenomena."