The Chinese word tai chi (taiji) refers to the ancient concept of yin and yang. Yin yang theory is one of the most important concepts in Chinese culture and has been hugely influential all around the world.
The Chinese see the yin yang theory as the governing principle behind all movement, all energy and all life in the universe. It explains how everything relates to everything else from the expansion of the universe to the movement of the smallest atomic particles.

Yin and yang are words almost everyone has heard of yet they are still poorly understood in the West. Yet they are simple to understand although the idea is grandiose in concept.
Yang describes any force that rises, expands, becomes lighter and more expressive. Signified by the heavens.
Yin describes any force that sinks, contracts, becomes darker, heavier, more still. Signified by the earth.
Nothing is either yin or yang until it changes or is compared to something else. When it changes it either moves towards yin or towards yang.
Examples of yin and yang
- The universe is constantly expanding – that is a yang force. Yet within it are points of extreme contraction. These are the stars and planets that generate their own gravity which is a yin force.
- Water expresses both yin and yang. It is fluid and non resisting which is yang yet it constantly seeks the lowest points which is a yin aspect. When water becomes too yin it freezes becoming cold and solid, both yin aspects. When water boils it becomes steam which rises and expands, both yang aspects.
- Strength is often described as a yang quality but it depends how you define strength. There are many kinds and there are big differences between a strong smell, a strong person and a strong iron bar. The smell and the person could be said to be yang but a strong iron bar is showing how solid and contracted it is so it would be yin.
Examples of yin and yang are all around us. Winter is yin, spring is becoming yang, summer is warm and expressive so fully yang then in autumn the leaves start to fall and nature begins its return to the ultimate yin of winter.

The yin yang symbol
Everyone is familiar with the yin yang symbol as seen above. It is often used to signify anything Chinese or a bit new age or anything to do with balance. But what does it mean?
The fact that it’s in a circle represents firstly that the flow of yin and yang is a never ending cycle. It also represents that yin and yang are happening everywhere within our observable universe and, we can deduce, everywhere we can’t see as well.
On the left the lighter area (yang) is rising upwards and expanding outwards to fill the space in the upper half. At the same time the darker area (yin) is sinking down to fill the space in the lower half.
Unfortunately, all too often the symbol is shown upside down with the yang half flowing downwards. Or, even worse, is shown on its side. Now you know which way round it should be and why.
The yin dot in the middle of the yang side and yang dot on the yin side signify that nothing in the universe is all yin or all yang. Nature is constantly seeking a balance so before anything becomes too much of yin or yang it starts to move the other way again.
Yin yang theory and tai chi
Tai chi chuan is based on the concepts of yin and yang. As you learn the postures and movements certain parts of your body become heavy while others become lighter. Some movements contract in while others expand out. This creates a flow of energy through your body that the Chinese call qi (pronounced chee).
This floating and sinking, contraction and expansion, movement and stillness in mind, body and breathing is what makes tai chi so powerful in restoring health and balance to unbalanced individuals.