My rendition of the first part of chapter four of Can Tong Qi (周易參同契):
And Confucius wrote to praise the profundity of “I”, the wisdom of Qian and Kun (乾坤) covering all vastness. From the earliest Emperor, and from the time when the poem of romantic love Guan Hui (關睢) was first praised, the mating of Male and Female has meant mixing chi together, and this practice began from the earliest year. The sage recognized this Heavenly signification through watching the Sky. The signifying symbols advance and retreat as well as bend and extend in definite patterns. When the Returning Hexagram (復卦) appears, it is the time for (re)birth, the Son takes the body of the Father, and upon the Mother the new establishment begins. The message begins at the center, and running up and down according the North Star.
Paul's comment: The author was highly knowledgeable about ancient texts and used them freely. The Retuning Hexagram says (based on Wilhelm's translation):The idea of a turning point arises from the fact that after the dark lines have pushed all of the light lines upward and out of the hexagram, another light line enters the hexagram from below. The time of darkness is past. In Taoist meditation, it is the approaching to absolute void that chi arises (in DanTian), signifying from death to rebirth. The phrase in this passage "the Son takes the body of the Father, and upon the Mother the new establishment begins" does sound very familiar to students of the psychology of the Unconscious, in particular of the Jungian type. The Father (Superego) has to "die" to make way for the Son (Ego) to couple with the Mother (Anima: Jungian female archetype of the Unconscious), as the first stage of the individuation process. In Taoist lingo, the beginning step to approach Tao.