Beyond the basic flow of yin and yang we advance to the concepts of the Five Phases. I prefer the expression Five Phases to the more common apellation of Five Elements. To a western mind the word element connects to the ideas of the ancient Greeks and the periodic table. It conveys components which are static, unchanging and discrete. In yin and yang is the essence of constant change. The expression Five Phases better reflects the fluidity of nature in yin yang theory. The Five Phases are Wood (木 mù), Fire (火 huǒ), Earth (土 tǔ), Metal (金 jīn), and Water (水 shuǐ). This order of presentation is called the “mutual generation” (相生 xiāngshēng) sequence. There is also an order of “mutual overcoming” (相剋/相克 xiāngkè), which is Wood, Earth, Water, Fire, and Metal.
The Five Phases theory further expands the changing cycles of yin and yang into five stages of transformation. These phases represent the seasons of the earth, characterized as wood, fire, earth, metal, and water. All of the Five phases are apects of qi. They are applied to many aspects of life, among them the seasons. Wood is appplied to spring, a period of 72 days, as are all the seasons. It is the period of growth, which generates abundant wood and vitality. Fire is matched with summer, understanably, a period of heat, energy and in many parts of the world the outbreak of real fires. It is an expanding, flowering period. Earth is associated with a dual application, assigned to a fifth season know as late summer or long summer, which is one of leveling, moderating and fruition. In some cases is is used with a set of in-between, transitional periods. Metal is linked with the autumn period of harvesting and gathering. Finally, water is paired with winter,the period of contraction, retention and retreat.
The phases have relationships to each other. In the generating cycle, Wood feeds Fire; Fire creates Earth; Earth bears forth Metal, Metal collects Water; Water nourishes Wood. In the overcoming sequence, Wood parts Earth. Think of tree roots penetrating through the ground upheaving sidewalks and you have the idea. Earth dams, absorbs and clouds Water. That water extinguishes fire is obvious, as is that fire melts metal. Finally, metal cuts wood. This is certainly true in the case of axes and saws.
One major area where the Five Phases are applied to human activity is Traditional Chinese Medicine. The Fives Phases are also said to correspond with the stages of human life: birth, growth, maturation, death, and rebirth. In TCM the body is considered as a whole and the systems and organs analyzed in terms of yin and yang. Some organs are considered basically yin in nature and others basically yang. The yin organs are the liver, heart, spleen, lungs, and kidneys. The yang organs are the gall bladder, stomach, large and small intestine and urinary bladder. The organs are paired a yin to a yang which share meridians, tissues, muscles, and energetic functions and also correspond to one of the Five Phases: The liver/gallbladder pair is Wood; the heart/small intestinepair is Fire; the spleen/stomach pair is Earth; the lungs/large intestine pair is Metal; and the kidney/bladder pair is Water.
Another area where the Five Phases are important is in feng shui. The origin of feng shui has it’s roots in locating a grave site that would ensure the happiness of the deceased. Unhappy ancestors were not a good thing for family well being as they would then not interceed with the gods in the spirit world. The practice spread to palaces and temples and then to the dwellings of ordinary people. Household harmony and business success were believed to be impacted by the way qi circulated. In feng shui the Five Phases correspond to this movement of energy or qi in the environment. Wood represents upward energy; fire represents a radiating energy; earth signifies an inward moving energy; metal is a contracting energy and water represents an expanding and penetrating energy.