The ‘qualities’ of the Five Phases or Wu Xing refer to the specific and intrinsic properties of Wood, Fire, Earth, Metal and Water. Each phase’s nature is to produce characteristic movements or transformations based on several specific manifestations of Yin and Yang. An early description of the Five Phases is found in the Hong Fan section of Shujing or commonly translated as ‘The Great Plan’ of the ‘Book of Documents. While neither Yin Yang nor Wu Xing exists in reality, they are systems of organization that can help us understand the “processes that are occurring in both nature and the microcosm that is the body.” These organizational relationships and processes are but an expression of heavenly energies that manifest on earth and within humans. This is how human life is considered to be situated between heaven and earth and why “our physical form may be most visible” while “it is our Qi that is everything and lasts forever.” The Five Phases are, in the simplest terms, a way of defining and understanding these transforming energies.

Water and Fire are opposites and create a polarization similar to that of Yin Yang theory. While Water’s main action is to descend, Fire characteristically ascends. This is can be demonstrated by their purely physical forms, such as Water seeking to collect at the lowest point of a vessel or Fire’s ability to form flames that peak above what is actually burning. Water (shǔi) is characterized by nourishing Yin properties such as moistening, humidifying, and soaking actions that are capable of gathering what is necessary to support life. Its flow can range from an illusive trickle as raindrops gather in the center of leaves to a tumultuous river that carves ravines and carries earth downstream. In all instances, Water is a collecting force that merges with that which it encounters.

Fire (hǔo) is Yang in nature with warming, energizing and illuminating properties. It provides energy and light in abundance for reaching the highest potential such as that seen in a perfectly ripening fruit. Fire in balance provides just the right amount of energy to reach a peak. Imagine this quality observed on the scale of a single flame as it produces and disperses a slow and steady warming energy. A similar property is found in maturing fruits, especially those with high-energy content and warmth like litchi and sweet peppers. If it goes unchecked, however, fire’s immense energy can rage out of control and take over suddenly like a wildfire or spiking fever.

The Wood and Metal phases blend qualities of both Yin and Yang. Wood can be considered slightly more Yang in nature while metal is more Yin. This is related to the Generating (Sheng) Cycle since Wood becomes the Yang-like Fire and Metal becomes the Yin-like Water. The primary action of Wood is to stand erect but remain flexible while Metal is meant to obey and change form. Wood (mù) embodies the characteristics of a plant’s ability to bend in resistance to force and straighten to follow the pattern of light movement through the day and seasons. Something considered a weed, such as crab grass, might have strong Wood properties: springing up overnight and while initially appearing delicate it develops a strong trunk and roots that allow it to resist being tramped or easily uprooted. Wood expands out in all directions like a plant simultaneously taking root into the earth and extending up towards the sky. That which is easily bent, surprisingly hard to break, and quick to recover can be considered to have strong Wood properties.

The defining power of Metal (jīn) comes from its capacity to shape and define. It is yielding and condensing like Yin and modifying like Yang. Metal is capable of transmitting electrical and magnetic energies and thus is associated with the forces of rhythm and gravity. While Wood embodies the outward movement of a plant growing, Metal energy is expressed inward like a flower closing and forming seeds. The condensing and recycling action of Metal produces seeds, precious gems, and ores that have the ability to store potential that may give rise to new life or form.

The Earth (tǔ) phase creates stability for the other four phases by providing a center. This center allows for receiving and giving just as the physical earth receives seeds that are transformed into crops for harvest. Earth essentially provides a foundation to stabilize and harmonize the other four phases. Earth, as a planet, is the basis for the reflection of heavenly energies that are expressed as the Five Phases and beginning to make these connections brings us as humans closer to comprehending the oneness of all phenomena.