He who knows the male, yet cleaves to what is female, Becomes like a ravine, receiving all things under heaven; And being such a ravine, He knows all the time a power that he never calls upon in vain.
Jung cites the Tao Te Ching to establish the ravine as the supreme symbol of receptive, feminine selflessness whose paradoxical yield is inexhaustible power — a key analogue for the psychological attitude of the self in harmony with Tao.
, Psychological Types, 1921thesis