Many natural dualities (such as light and dark, fire and water, expanding and contracting) are thought of as physical manifestations of the duality symbolized by yin and yang. It is believed that the organization of qi in this cosmology of yin and yang has formed many things. In the cosmology pertaining to yin and yang, the material energy, which this universe has created itself out of, is also referred to as qi. It can be compared with the old wuji (無極, 'without pole'). 'great pole') is a Chinese cosmological term for the 'Supreme Ultimate' state of undifferentiated absolute and infinite potential, the oneness before duality, from which yin and yang originate. Taiji or Tai chi (simplified Chinese: 太极 traditional Chinese: 太極 pinyin: tàijí lit. Yin is the receptive and yang the active principle, seen in all forms of change and difference such as the annual cycle (winter and summer), the landscape (north-facing shade and south-facing brightness), sexual coupling (female and male), the formation of both men and women as characters and sociopolitical history (disorder and order). In Chinese cosmology, the universe creates itself out of a primary chaos of material energy, organized into the cycles of yin and yang and formed into objects and lives.

Yin and yang is a Chinese philosophical concept that describes interconnected opposite forces. Yin-dark on the right and yang-light on the left

The Two Aspects of Taiji, also known as the yin-yang symbol

History of yin yang philosophy