Chinese Taoists referred to the universal life force as ‘Chi’, this is based on the principle that everything exists in a pair of opposites.
The I Ching introduced Yin and Yang to us in the second century BC, which positions, Yin and Yang behind Chi on the pyramid of life. Underneath are the five elements of the natural world.
Nothing is ever Yin or Yang, it is always both of these extremes.
Below is the Yin and Yang symbol:
Everything in the universe is both Yin and Yang, sometimes more of one than the other - Chinese philosophy and medicine always maintains an equal measure, otherwise there is disease.
Yin and yang is used a lot in love spells and witchcraft spells.