Traditional Chinese Medicine Speedrun: Yin–Yang and The Five Agents

Note: The author is a student at the Justao TCM Institute in Shanghai, China, and is not a licensed physician.

Yin–Yang and the Five Agents are the foundations of Traditional Chinese Medicine (TCM). While these concepts might seem difficult and mysterious—not only to foreigners, but even to native Chinese speakers—they are, at their core, simply two classification methods.

Tai-chi (太極)

Not Kung-fu. No.

Tai-chi is simply the thing as a whole that you want to classify. After deciding what is the Tai-chi, you can decide how to classify it, using the methods below.

Yin–Yang (陰陽)

Simply binary.

Yes. I’m not joking.

The core of Yin–Yang theory is to classify anything into two parts. For example, death is Yin, and life is Yang. Night is Yin, and day is Yang.

Five Agents (a.k.a. Five Elements) (五行)

Simply the Pro Max version of Yin–Yang. They classify things into two; we classify things into five.

The order of the Five Agents is: Wood (木), Fire (火), Earth (土), Metal (金), and Water (水). Wood and Fire are Yang, Metal and Water are Yin, and Earth sits between them.

Why this specific order? Because they generate each other in this order (the generative cycle).

Let’s use an example:

• Wood burns as fuel, which generates Fire

• Fire produces ashes, which are equivalent to Earth

• Earth includes Metal in it

• Metal condenses moisture into Water

• Water supports the growth of Wood

and it repeats.

In addition to the generative cycle, the Five Agents also restrain each other through what is called the destructive cycle (相剋). You don’t need to memorize a new order—it simply moves two steps forward each time, compared to one step forward in the generative cycle.

In this pattern:

• Wood restrains Earth (like how roots penetrate soil)

• Earth restrains Water (like how soil absorbs water)

• Water restrains Fire (like how water extinguishes fire)

• Fire restrains Metal (like how fire melts metal)

• Metal restrains Wood (like how metal cuts wood)

In TCM, the Five Agents are also used to categorize the five major organ systems:

• Wood → Liver (肝)
• Fire → Heart (心)
• Earth → Spleen (脾)
• Metal → Lung (肺)
• Water → Kidney (腎)

These are not just anatomical organs in the modern biomedical sense, but functional systems in your body.

Conclusion

Don’t study TCM. Unless you want to.