Yin and Yang and the Five Phases (Wuxing): Chinese Cosmology

Yin and yang are the two complementary forces of Chinese cosmology: yin the dark, cool, receptive and descending aspect of things, yang the bright, warm, active and ascending one, each containing the seed of the other and turning into it in endless alternation. Together with the five phases (wuxing) of wood, fire, earth, metal and water, they form a system of "correlative" thought, developed between the fourth and second centuries BCE, that underlies Taoism, Confucian cosmology, Chinese medicine, astrology, feng shui and the calendar.

The Meaning of Yin and Yang§

In the oldest Chinese texts, yin (陰) referred to shade, overcast weather or the north side of a mountain and the south bank of a river, and yang (陽) to sunshine and the south slope. From these concrete meanings the words came to name two aspects present in every phenomenon. Yin is associated with darkness, cold, moisture, rest, the earth, the moon, the interior and the feminine; yang with light, heat, dryness, movement, heaven, the sun, the exterior and the masculine.

Three ideas define the pair. First, they are relative: something is yin or yang only in relation to something else; the front of the body is yin relative to the back, but the upper body is yang relative to the lower. Second, they are interdependent: neither exists without the other, and each contains a germ of its opposite. Third, they transform: when yang reaches its peak it begins to turn into yin, as midsummer leads to winter and noon to night. Unlike the dualism of good and evil in some religions, yin and yang are not moral opposites; health and order come from their balance.

The "Great Commentary" (Xici) attached to the I Ching states that "one yin and one yang: this is called the Tao". In the I Ching itself, unbroken lines are yang and broken lines yin, and the sixty-four hexagrams can be read as patterns of their alternation.

The Five Phases (Wuxing): Wood, Fire, Earth, Metal and Water§

The word wuxing is often translated "five elements", but xing means to move or act, and scholars such as Joseph Needham and A. C. Graham prefer "five phases", "five agents" or "five processes". They are not basic substances from which things are built, like the Greek earth, water, air and fire, but five modes of change through which things pass.

An early list appears in the "Great Plan" (Hongfan) chapter of the Book of Documents, whose date is debated, which describes water as soaking and descending, fire as blazing and rising, wood as bending and straightening, metal as yielding to and taking shape, and earth as receiving seed and giving harvest. By the third century BCE the phases had been linked to seasons, directions, colours and many other categories.

The four directional animals, the Azure Dragon of the east, the Vermilion Bird of the south, the White Tiger of the west and the Dark Warrior (a tortoise entwined by a snake) of the north, belong to the same scheme.

Cycles of Generation and Overcoming§

The phases relate to each other in two main sequences.

• The generating (mutual production) cycle: wood feeds fire; fire produces earth (ash); earth bears metal; metal gives rise to water (condensation, or springs from rock); water nourishes wood.
• The overcoming (conquest) cycle: wood overcomes earth, as roots break the soil; earth dams water; water quenches fire; fire melts metal; metal cuts wood.

Later theorists added secondary relations, such as one phase "insulting" or "over-acting on" another, which proved useful in medicine for describing disorders. These cycles allowed thinkers to explain change, succession and imbalance in nature, the body and history in a single framework.

Correlative Cosmology: Zou Yan, the Huainanzi and Dong Zhongshu§

The philosopher Zou Yan (c. 305–240 BCE), whose writings are lost, is remembered as the leading figure of a "School of Yin and Yang". According to later accounts he taught that dynasties succeed one another according to the conquest cycle of the phases, each ruling by the "virtue" of one phase. The First Emperor of Qin adopted water as his dynasty's phase, with black as its colour; the Han changed their official phase more than once, from water to earth and eventually to fire.

The Annals of Lü Buwei (Lüshi chunqiu, c. 239 BCE) arranged government by the "monthly ordinances", prescribing for each month of the year the colours, foods, music and policies proper to its phase. The Huainanzi (presented to the Han court in 139 BCE) integrated yin-yang and five-phase cosmology with Taoist ideas of the Tao. The Confucian Dong Zhongshu (c. 179–104 BCE) made the system the basis of a moral and political cosmology, in which Heaven responds to the ruler's conduct with portents. A. C. Graham called this style "correlative thinking": understanding the world by systematic analogies between classes of things, rather than by chains of mechanical cause.

Yin-Yang and the Five Phases in Medicine, Divination and Feng Shui§

The Inner Classic of the Yellow Emperor (Huangdi neijing), compiled during the Han from earlier materials, applied yin-yang and the five phases to the body. Each organ belongs to a phase, illness is understood as imbalance, and diagnosis traces how disturbance in one phase affects others through the generating and overcoming cycles. This framework remains central to traditional Chinese medicine, and practices such as qigong and inner alchemy use its vocabulary.

In Chinese astrology, the ten heavenly stems are paired as yang and yin forms of the five phases, and a person's birth chart is analysed for the balance of phases. In feng shui, landforms, directions and dates are classified by phase to judge whether a site is harmonious. The Chinese calendar, almanacs, music theory and even the colours of imperial ceremony followed the same correspondences. Comparable systems of correspondences exist in Western esotericism, though they developed independently.

The Taiji Symbol and the Supreme Ultimate§

The most famous image of yin and yang is the taijitu, "diagram of the Supreme Ultimate": a circle divided by an S-shaped curve into black and white halves, each containing a dot of the other colour. Although it is now a universal emblem of Taoism, its familiar form is relatively late; versions close to it are documented in Ming-dynasty works from around the fourteenth to sixteenth centuries.

The concept of the Supreme Ultimate (taiji) is older. The "Great Commentary" of the I Ching says that the changes contain the Supreme Ultimate, which produces the two modes, yin and yang. In the eleventh century the Neo-Confucian Zhou Dunyi wrote a short explanation of a diagram of the Supreme Ultimate, which showed a sequence of circles: an empty circle, a circle of interlocking yin and yang bands, the five phases, and the production of all things. The diagram probably had Taoist antecedents, and it became a foundation of Neo-Confucian metaphysics.

Modern Uses and Misunderstandings§

Outside China, yin and yang are often reduced to a simple opposition of male and female or good and bad, and the five phases are presented as an equivalent of the Western elements. Both simplifications obscure the dynamic, relational character of the original ideas. Historians also caution against treating correlative cosmology as timeless "ancient wisdom": it was systematised at a particular time, by identifiable thinkers, and it varied between schools. The system nevertheless remains a living framework in Chinese medicine, martial arts, the calendar and religious practice, and the taijitu is used on the flags, temple roofs and robes of Taoism worldwide.

Frequently asked questions§

What do yin and yang mean?§

Yin originally meant the shady side of a hill and yang the sunny side. In Chinese thought they name complementary aspects of all things: yin is dark, cool, receptive and still; yang is bright, warm, active and moving. They are interdependent and constantly transform into each other.

What are the five elements in Chinese philosophy?§

They are wood, fire, earth, metal and water. Scholars prefer to call them the five phases or agents, because they describe stages of change rather than fixed substances, and they are linked to directions, seasons, colours, planets and bodily organs.

Is yin bad and yang good?§

No. Yin and yang are not moral categories. Each is necessary, each contains the other, and harmony comes from their balance. Excess of either is considered a source of disorder in the body, society or nature.

Sources and further reading§

• Yin-Yang and the Nature of Correlative Thinking — A. C. Graham, 1986
• Yinyang: The Way of Heaven and Earth in Chinese Thought and Culture — Robin R. Wang, 2012
• Science and Civilisation in China, vol. 2: History of Scientific Thought — Joseph Needham, 1956
• Heaven and Earth in Early Han Thought — John S. Major, 1993
• The Huainanzi — John S. Major, Sarah A. Queen, Andrew Seth Meyer and Harold D. Roth (trans.), 2010
• Medicine in China: A History of Ideas — Paul U. Unschuld, 1985
• Disputers of the Tao — A. C. Graham, 1989