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☯️ What Exactly Is Yin-Yang?

Understanding the Fundamental Principle of TCM Through the Law of Change

What exactly is Yin-Yang? There are countless answers to this question. Anyone who studies Traditional Chinese Medicine can offer their own interpretation. I’m no exception. For a question with no definitive answer, perhaps the best we can do is to continuously pursue the most convincing explanation.

🌍 East vs West: Two Different Questions

The Western Question: “What is the world made of?”

The most fundamental question posed by ancient Greek philosophers seems to have been: “What is the world made of?”

Thales

The origin of the world is water

Heraclitus

The origin of the world is fire

Aristotle

The world consists of four elements: earth, water, fire, and air

This question evolved with the development of modern science:

“If we keep dividing matter, what happens?
Won’t the last remaining substance be the basic building block of the universe?”

➡️ This led to the discovery of atoms, nuclei, and subatomic particles.

The Eastern Question: “What is the law of change?”

So, while Western philosophers were shouting “Eureka!” in search of the most fundamental substance, what were Eastern philosophers pondering?

易經 (I Ching / Book of Changes)

易 = Change

The book Confucius studied so intensely that he broke the binding leather straps three times

Our ancestors, under the fundamental principle that the world constantly changes, sought to find the laws governing that change.

🔬 Western Approach

“What is the world
made of?”

Matter-Centered

☯️ Eastern Approach

“What is the law
of change?”

Change-Centered

💡 Interesting Fact: We already learned about atoms, neutrons, calcium, potassium, sodium, and the periodic table in high school. But what have we learned about the “law of change”? As practitioners of TCM, we’ve actually learned much: Yin-Yang, Three Yin Three Yang, Eight Trigrams, Five Elements, etc.

🔄 Searching for the Minimal Unit of Change

When the West found earth, fire, water, and air as the minimal units of matter, what did the East find as the minimal units of change?

🤔 Let’s Think About This

Change, in any form, requires some kind of movement.

Then wouldn’t the most basic unit of change be…

Moving ⚡

Stillness ⏸️

💡 Key Discovery

While minimal units of matter have no pairs, minimal units of change mostly require pairs:

Stillness ↔ Movement
Gathering ↔ Dispersing
Converging ↔ Diverging
Compressing ↔ Expanding
Diminishing ↔ Amplifying

📖 Learning Yin-Yang from the Yellow Emperor’s Classic

故積陽爲天, 積陰爲地.
陰靜陽躁, 陽生陰長, 陽殺陰藏.
陽化氣, 陰成形.

When Yang accumulates, it becomes Heaven; when Yin accumulates, it becomes Earth.
Yin is static and Yang is dynamic.
When Yang generates, Yin grows; when Yang diminishes, Yin stores.
Yang transforms into Qi (energy flow), Yin forms into shape (matter).

— From Huangdi Neijing (Yellow Emperor’s Classic), Yin Yang Ying Xiang Da Lun —

🎬 Understanding Yin-Yang Through Motion Pictures

When I first studied Chinese medicine, the biggest challenge was the matter-centered thinking ingrained from over ten years of Western science education.

💡 Key Insight: If we remember that Eastern philosophy seeks to explain the laws of change, then explaining movement through matter is fundamentally contradictory.

🏃 Example: How to explain “running”?

Dictionary definition: “To move very quickly by moving one’s feet rapidly”

➡️ Mostly verb-based expressions. It’s not easy to define change or movement linguistically.

📸 Matter or nouns can be expressed through photographs or drawings.
🎥 However, change or verbs are much more difficult. One method? Show it as a “video”!

🌌 Understanding Through the Post-Big Bang Universe Formation

What video should we imagine when we read “When Yang accumulates, it becomes Heaven; when Yin accumulates, it becomes Earth”?

🌠 Post-Big Bang Universe Video

Stage 1: Beginning of Movement

From a state of cosmic dust, particles begin moving in a certain direction.

Stage 2: Formation of Flow

As they move in certain directions, patterns emerge, and as they rotate repeatedly, bands begin to appear.

Stage 3: Condensation and Clarification

Some parts clump together, and these clumped parts gain gravity, pulling in surrounding matter and growing larger, while the areas where dust has disappeared become clean and clear.

✅ Reading the Yellow Emperor’s Classic Through Video

積陽爲天 — When Yang accumulates, it becomes Heaven

➡️ Movement accelerates

積陰爲地 — When Yin accumulates, it becomes Earth

➡️ Stops and clumps together

陰靜陽躁 — Yin is static and Yang is dynamic

➡️ This is the definition itself

陽生陰長, 陽殺陰藏 — When Yang generates, Yin grows; when Yang diminishes, Yin stores

➡️ When flow accelerates, clumping also grows larger; when flow slows, clumping becomes smaller

陽化氣, 陰成形 — Yang transforms into Qi, Yin forms into shape

➡️ Moving and dispersing creates flow (Qi), while clumping creates form (shape)

🔥 Evolution of Yin-Yang Understanding: Beyond the Candle Metaphor

🕯️ First Stage: Material Understanding

When explaining Yin and Yang to patients, I often simplify by saying Yin is matter and Yang is energy.
Using a candle as a metaphor: the wax body is Yin and the flame is Yang.

In fact, this was my first stage of understanding Yin and Yang.

💡 Realization: TCM Terms Are Verbs, Not Nouns

After realizing that most TCM terminology is verbs rather than nouns, and that they describe change, I came to think that my understanding of Yin-Yang was only partial.

❌ Incorrect Understanding

Yang = Heat = Clear = Restless
(directionless equivalence)

➡️

✅ Correct Understanding

Moving, dispersing, expanding
therefore
hot, clear, and restless

🎯 Conclusion

Yang (陽): Moving → dispersing → expanding → therefore hot, clear, and restless

Yin (陰): Stopping → gathering → compressing → therefore cold, turbid, and calm

✨ Paradigm Shift: Three Core Principles

Here are the crucial shifts in perception I had to make to reach this conclusion.

1️⃣ Abandon Matter-Centered Thinking

Chinese medicine is thoroughly a study of change.

We all know that the Five Elements are not like Aristotle’s four elements, claiming the world consists of five substances: Wood, Fire, Earth, Metal, and Water. They are symbolic representations of natural change patterns. Three Yin Three Yang, Six Channel Pattern Identification, the flow of Qi — Chinese medicine is not about fixed matter but about the changes and flows of living, pulsating nature and the human body.

2️⃣ Change Is Hard to Explain with Nouns

Think of TCM terminology as verbs and visualize videos.

If you think of TCM terms only as nouns, there’s no way to explain why Tai Yang is associated with Cold Water (寒水). Yin-Yang is not something (matter, noun) before it is a kind of change (movement, verb). When interpretation of classical texts gets stuck, thinking this way has been very helpful.

3️⃣ The Definition of Yin-Yang

Yin (陰)

Means change that stops, gathers, converges, compresses, and diminishes.

Yang (陽)

Means change that moves, disperses, radiates, expands, and amplifies.

This is the first step in understanding Yin-Yang.

🌿 In Closing

This is my current understanding of Yin-Yang.

For a question with no definitive answer, the best we can do is to continuously pursue the most convincing explanation.

This article is written to confirm where I am somewhere along that journey of seeking.

Acknowledgment: Most of the concepts and approaches discussed in this article were learned from Dr. Hye-Jung Jang’s blog, where she explores physics-based approaches and interpretations of Chinese medicine through her series “Medicine of Physics” in Minjok Uihak Sinmun (Korean Traditional Medicine Newspaper). I have digested and adapted these ideas in my own way.

This article is based on the knowledge and clinical experience of Dr. Byoungjin Na, Doctor of Traditional Chinese Medicine, with editorial and organizational assistance from ChatGPT and Claude AI.

Dr. Byoungjin Na, Dr.TCM
Director of GreenLeaf Acupuncture & Herb Clinic
Healthy Body, Healthy Mind.

What Exactly Is Yin-Yang?