Civilization in Transition (The Collected Works of C. G. Jung, Volume 10)
A human relationship leads into the world of the psyche, into that intermediate realm between sense and spirit, which contains something of both and yet forfeits nothing of its own unique character.
Into this territory a man must venture if he wishes to meet woman half way.
Circumstances have forced her to acquire a number of masculine traits, so that she shall not remain caught in an antiquated, purely instinctual femininity, lost and alone in the world of men.
So, too, man will be forced to develop his feminine side, to open his eyes to the psyche and to Eros, It is a task he can’ not avoid. Carl Jung, CW 10, Page 125.