Taoist Cosmology, a story about the origin of universe

Every spiritual tradition has a defined (or implied) cosmology: a story about the origin of the universe - about how the world as we perceive it comes into existence. The story that Taoism tells goes something like this … In the beginning is wuji, or Tao – an undifferentiated Unity, beyond vibration.
 
From this emerges taiji – vibration/qi in its complementary aspects of Yin and Yang. It is the "dance" – i.e. the continual transformations -- of Yin & Yang that fuels the flow of qi. This stage represents the emergence of duality/polarity out of the Unity of Tao.

1. From this dance of Yin and Yang emerges the five elements: wood (lesser yang), fire (greater yang), metal (lesser yin), water (greater yin), and earth (central phase). Also produced here are the eight trigrams – Bagua -- which form the 64 hexagrams of the Yijing (I Ching). This stage represents the formation, from the initial Yin/Yang duality, of the elemental constituents of the phenomenal world.

2. From the five elements come the "ten-thousand things," i.e. all of manifest existence, all of the inhabitants of the world that we experience.

Another way of describing this process is to say that these stages represent the descent of consciousness into form.

Taoist practitioners, using various Inner Alchemy techniques, are able to reverse this sequence of events, to return to the realm of Tao.