Yin-Yang theory developed many thousands of years ago in China and has been a mainstay of Chinese thought and culture ever since. In a nutshell, Yin-Yang represents the duality of all things in the natural world. The theory can be used to describe and philosophize on everything since the Big Bang. To clarify further, there are 5 basic tenets to Yin-Yang theory:

1. Opposition - This is the idea that something cannot exist without it's opposite or counterpart existing as well. For example, you cannot have good without bad; day without night; left without right; up without down; in without out.

2. Relativity - Einstein's theory of relativity was uncovered in Yin-Yang theory thousands of years prior - and without all that math! While I am big relative to my 5-year old son, I am small relative to Michael Jordan. My 3-year old daughter is small relative to my son, and big relative to her favorite doll. Get my point? It is all relative.

3. Infinitely divisible - Depending on the specific topic, one can break down the Yin-Yang nature of things infinitely. Someone or something will always be bigger or smaller, higher or lower, further in or further out than the next. Science continues to unveil smaller and smaller particles that make the foundation of all things in the universe and at the same time the universe continues to expand and grow beyond our imaginations.

4. Mutual consumption - The two aspects of Yin and Yang are never fixed or static, instead they are continuously transforming and consuming one-another. For example, day does not suddenly become night. It constantly moves toward the night from it's brightest point at high noon. And night gradually becomes the day from it's darkest point at midnight.

5. Transformation - At the extremity of one begins the other. So the end of Yin marks the beginning of Yang and so on. For example, at the end of the day (dusk) begins the night and at the end of the night (dawn) begins the day.

So here's a quick list of what would qualify as Yin vs. Yang. Remember that all things in nature can be separated into Yin-Yang pairs!

YIN --------- YANG
Feminine --- Masculine
Curved/Round – Straight/Square

Dark/Night/Moon --- Bright/Day/Sun
Material --- Immaterial

Emotional --- Logical
Nourishing --- Energetic

Yin-Yang theory is at the basis of Chinese medical diagnosis and treatment. We say that health is balancing or harmonizing Yin and Yang. One can suffer from excess Yang energy, deficient Yin energy; excess Yin energy and/or deficient Yang energy. Treatment plans aim to supplement deficiencies while sedating excesses. It sounds simple, but can be very complex as the practitioner factors in all aspects of one's health. However, if you cannot break it down into Yin-Yang pairs, diagnosis and subsequent treatment will fail.

Author's Bio: 

Adam Shapiro is a Licensed Acupuncturist (L.Ac.) and holds a Masters
Degree in Traditional Chinese Medicine (MSTCM) from The Academy of
Chinese Culture and Health Sciences in Oakland, CA. Prior to becoming
an acupuncturist and herbalist, Adam studied several ancient martial
arts including Tai Ji, Bagua, Hsing-I, and Northern Shaolin Kung Fu,
as well as healing arts known as Qi Gong. Adam's love for these
Chinese internal arts paved the way for him to become a hands-on
healer sharing the gifts he's gained from over a decade of dedicated
study and practice.