In 1951, Toni Wolff—first a student, then a collaborator, and ultimately a romantic partner of C.G. Jung—published 'Strukturformen der weiblichen Psyche', in which she describes four archetypal forms of the female psyche, across two axes. Wolff’s archetypes are not personality types or fixed roles. They are structural potentials within the feminine psyche. Every woman may express aspects of all four, but typically one or two dominate her psychological development.