The five elements (Wu Xing): a cycle, not a chemistry set

"Five elements" is a translation that has caused a century of confusion. 五行 (wǔxíng) means five goings or phases — five stages in any process of change, named after five familiar materials because each material behaves like its phase. Wood grows, fire flares, earth holds, metal contracts, water sinks and stores. Nothing is "made of" wood; things behave like wood when they are in their growing phase.

The five phases

• Wood (木) — growth, expansion, beginnings. Spring, the east, green, morning, the liver in medicine, the trigrams Zhen and Xun.
• Fire (火) — peak activity, brightness, heat. Summer, the south, red, noon, the heart, the trigram Li.
• Earth (土) — centring, ripening, transition. Late summer and the turning points between seasons, the centre, yellow, the spleen, the trigrams Gen and Kun.
• Metal (金) — contraction, harvest, refinement. Autumn, the west, white, evening, the lungs, the trigrams Qian and Dui.
• Water (水) — storage, depth, stillness before renewal. Winter, the north, black, night, the kidneys, the trigram Kan.

Read down the list and you have a year, a day, a life. That is the point: the five phases are yin and yang unfolded into a cycle with a beginning, a climax, a turn, a decline and a rest.

Two cycles

Everything practical about the five phases comes from two sequences.

The generating cycle (相生, xiāngshēng): wood feeds fire, fire makes ash and so earth, earth bears metal, metal (when cold) gathers water, water nourishes wood. Each phase is the "mother" of the next and the "child" of the previous. Growth, support, nourishment.

The controlling cycle (相剋, xiāngkè): wood breaks up earth, earth dams water, water quenches fire, fire melts metal, metal cuts wood. Each phase restrains the one two steps ahead of it. Limits, structure, discipline.

Neither cycle is good or bad. A system with only generation runs away with itself; one with only control starves. The tradition adds two pathologies: over-control (相乘), when a controller is too strong and crushes what it should merely check, and reverse control (相侮), when the controlled phase is so strong that it insults its controller — water so abundant that it puts out nothing and instead swamps the earth meant to contain it.

In the body and the kitchen

Traditional medicine maps the five phases onto organ systems and uses the two cycles as a diagnostic grammar: a liver (wood) problem may "attack" the spleen (earth), a kidney (water) deficiency may fail to "nourish" the liver (wood). Foods, flavours (sour, bitter, sweet, pungent, salty) and seasons are sorted the same way. Whether or not one takes the physiology literally, the grammar is consistent and old.

In BaZi

The Four Pillars are written in ten Heavenly Stems and twelve Earthly Branches, and every one of those twenty-two characters has an element (and a polarity). A chart is therefore an inventory of the five phases at the moment of birth. The reading asks two things:

• Balance. Which phases are abundant, which scarce or absent, with the month branch counting most because it sets the season.
• Relation to the Day Master. The stem of the day pillar is "you"; the other characters are classified by whether they generate you (Resource), are generated by you (Output), are controlled by you (Wealth), control you (Officer) or share your phase (Companion). Those five relations, each in yin and yang form, are the Ten Gods.

From the balance follow the chart's favourable elements (喜用神): the phases that would steady a chart that is too strong or too weak. Our calculator shows the element count, the Day Master's strength and the favourable elements, with the rule it used.

In the I Ching

The eight trigrams carry elements (see the eight trigrams), and Plum Blossom numerology reads the body and use trigrams of a hexagram through the generating and controlling cycles: use generating body is favourable, use controlling body is not. The main I Ching tradition, by contrast, is built on yin and yang and the trigram images rather than the five phases — the two systems grew up separately and were braided together in the Han.

A way to think, not a periodic table

The five phases are most useful as questions. Where in the cycle is this project, this season, this relationship? What generates it, and is that source being fed? What controls it, and is the control proportionate? Treated that way the scheme is a compact model of growth and limit, which is why it has survived in medicine, music, cooking, politics and the calendar long after the ancient physics it once accompanied was forgotten.