Though Yin and Yang can be understood individually, they cannot exist separately. They might seem like opposites and do typically represent two different sides of one coin but their properties are actually complementary and dependent on one another.
This indivisibility is a central aspect of Yin and Yang. Without Yin, Yang cannot exist. Without Yang, Yin is not present. Yin and Yang are inseparable; just as we cannot have only sunny days throughout the year, we will not only have cloudy either.
Another important element in Yin Yang theory is the concept that Yin and Yang can change into one another. Clouds can give way to sun in the same way that Yin can be transformed into Yang. Within Yin, the seed of Yang exists; within Yang, Yin is always present. As a consequence of this nature, Yin and Yang can be divided infinitely. Everything contains Yin and Yang. They are two opposite yet complementary energies. it is impossible to have one without the other. Both create a totality, a complete whole.
This inseparable and inter penetrating dynamic balanced relationship is reflected in the form of the Yin-Yang ( Taijitu) symbol. The small dots within each of the two energies (represented by black and white) symbolize that there is always some Yin (black) within Yang (white) and vice versa. No matter where you bisect the diameter of the whole circle, each half will always contain some Yin and some Yang.
Nothing is absolute with Yin and Yang. The designation of something as Yin or Yang is always relative to some other thing
Balance and Harmony – Yin & Yang
In the Asian/Chinese Yin-Yang model, Yin (the black) contains a seed of Yang (in the form of a white dot). There is Yin, but interestingly, Yin is also Yang because it contains some Yang. The truth is Yin can transform into Yang under certain conditions. It can do this because Yang is present in Yin. So there is balance, but the relationship goes beyond balance to one of harmony. When two things are balanced, they are equal but still separate. In a relationship of harmony, the two energies blend into one seamless whole, as perfectly embodied by the swirling Yin-Yang symbol.
Much of Taoist philosophy is based on the idea that everything goes in cycles – the years, the months, the seasons, even human life itself. These cycles are represented by the Circle of the Tai Chi, and the flow of time is indicated by the way the Yin and the Yang areas increase and decrease as they progress around the symbol.
This means there is a dynamic flow happening that automatically and continuously balances and rebalances these energies. In the natural world this phenomenon is seen in the changing of the seasons: the cold of winter yields to the warmth of spring and summer heat, and then gradually turns cool in fall to become winter once again. You can also see this perpetual balancing at work in a shorter time frame when a thunderstorm clears the air of an unusually hot and humid summer day.
Two halves that together complete wholeness. Yin and yang are also the starting point for change. When something is whole, by definition it is unchanging and complete. So when you split something into two halves yin / yang, it upsets the equilibrium of wholeness. This starts both halves chasing after each other as they seek a new balance with each other.