We are all energy. The Universe is energy.
Qi is the vital energy, life force, essential for our lives.
In traditional Chinese philosophy, "yuan" is the Original energy, Integral energy. It is the energy the Universe is made of, the energy before "Big Bang". It is the root of all changes, an undifferentiated energy.
From the Integral energy, yin and yang developed and, together, form the energy (qi) of all matter. Us, human beings, are microcosms in which yin and yang interact. A body with balanced yin and yang, is a healthy, energetic body and we are happy, fulfilled beings. We have pre-natal qi, the qi we received from our parents, and post-natal the qi, which we get from food. The post-natal qi could be enhanced by practicing qigong, the science of working with qi.
Our qi is influenced by everything we do, including what we eat, what we drink, our surroundings, people we interact with, etc.
Our qi is also influenced by our thoughts, emotions and desires.
The Five Element Theory describes in details and elaborate scheme of associations that shows how qi is influenced.
Here are some highlights:
The Five Elements are: Wood, Fire, Earth, Metal, Water.
Associated respective directions: East, South, Center, West, North.
Respective seasons: Spring, Summer, Long Summer, Autumn, Winter
Respective colors: Green, Red, Yellow, White, Black
Respective taste: Sour, Bitter, Sweet, Pungent, Salty,
Respective emotion: Anger, Happiness, Pensiveness, Sadness, Fear
Yin Organ: Liver, Heart, Spleen, Lungs, Kidneys
If you are interested in reading more, here are some resources:
http://en.wikipedia.org/wiki/Qigong
http://en.wikipedia.org/wiki/Jing_(Chinese_medicine)
Chinese Soaring Crane Qigong, Zhao, Jin-xian; translated by, Chen, Hui-xian
The Root of Chinese Qigong, Dr. Yang, Jwing-Ming
