The Ying & Yang

Introduction

In Chinese cosmology, Yin and Yang (see a picture)are two opposite but complementary principles that regulate the functioning of the cosmos. The repeated alternation of Yin and Yang provides the energy necessary for the cosmos to sustain itself. Their continuous joining and separation is at the origin of the rise and the disappearance of entities and phenomena within the world of the "ten thousand things" (wanwu) (Helmut, pp. 1-9).

Yin and Yang and the eight trigrams 

Discussion

According to a famous statement, which is found in one of the appendixes to the Book of Changes(Yijing), "one Yin and one Yang, this is the Dao." This sentence refers to the Dao that first determines itself as Unity (or the One), and then gives birth to the two complementary principles. As each of these stages generates the next one, Yin and Yang are ultimately contained within the Dao itself. At the same time, the phrase "one Yin and one Yang, this is the Dao" alludes to the continuous alternation of Yin and Yang within the cosmos. When one of the two principles prevails, the other yields, but once one of them has reached the height of its development, it begins to recede — and in that very moment, the other principle begins its ascent. This mode of operation is especially visible in the time cycles of the day (alternation of daytime and nighttime) and of the year (alternation of the four seasons) (Woolidge, pp. 12-26).

The origins of these notions are impossible to ascertain. It is generally deemed that the terms yin and yang originally denoted the shaded and sunny sides of a hill, and later began to be used in an abstract sense as cosmological categories. The earliest extant text that contains a list of items arranged according to their Yin and Yang qualities is a manuscript entitled Designations (Cheng, found in Mawangdui), probably dating from the third century BCE. Examples of Yang and Yin items, respectively, mentioned in this text include: heaven and earth; above and below; day and night; summer and winter; spring and autumn; man and woman; father and child; elder brother and younger brother; ruler and minister; soldiers and labourers; speech and silence; giving and receiving; action and non-action.

Between the third and the second centuries BCE, the notion of Yin and Yang became one of the pillars of the system of correlative cosmology. This system coordinates several patterns of cosmological emblems with one another, including Yin and Yang, the Five Agents, and the eight trigrams and sixty-four hexagrams of the Book of Changes. Each of these patterns represents a particular way of explicating the features and functioning of the cosmos. For example, Yin-Yang and the Five Agents are correlated as follows (Hoopes, pp. 58-63):

? Yin is related to the agents Metal (west/autumn) and Water (north/winter) ? Yang is related to Wood (east/spring) and Fire (south/summer) ? the balance of Yin and Yang is represented by the central agent Soil

The association of Yin and Yang with the Five Agents is at the origin of the view that Yin and Yang are further subdivided into two states ...