In Traditional Chinese Medicine, there are believed to be three different types of energy in the human body, known as "the three treasures. These are Jing, Chi (Qi) and Shen. Of these three, only Qi has received some recognition in the West so far. Qi is but one of the Three Treasures – the other two are equally wondrous.
The Three Treasures are the fundamental energies that maintain human life.
Master Sung Jin Park, used to describe the Three Treasures by comparing them to a burning candle. Jing is like the wax and wick, which are the substantial parts of the candle. They are made of material, which is essentially condensed energy. The flame of the lit candle is likened to Qi, for this is the energetic activity of the candle, which eventually results in the burning out of the candle. The radiance given off by the flaming candle is Shen. The larger the candle and the better the quality of the wax and wick, the steadier will be its flame and the longer the candle will last. The greater and steadier the flame, the steadier the light given off and the greater the light.
Jing existed before the body existed, and this Jing enters the body tissues and becomes the root of our body. When we keep Jing within our body, our body can be vigorous. If a person cares for the Cavity of Jing [a space within the lower abdomen], and does not hurt it recklessly, it is very easy to enjoy a life of great longevity. Without Jing energy, we cannot live.
Qi is the invisible life force which enables the body to think and perform voluntary movement. The power of Qi can be seen in the power that enables a person to move and live. It can be seen in the movement of energy in the cosmos and in all other movements and changes. Coming from heaven into the body through the nose (Yang Gate), it circulates through the twelve meridians [the energy circuitry of the body] to nourish and preserve the inner organs.
Shen energy is similar to the English meaning of the words "mind" and "spirit." It is developed by the combination of Jing and Qi energy. When these two treasures are in balance, the mind is strong, the spirit is great, the emotions are under control, and the body is strong and healthy. But it is very difficult to expect a sound mind to be cultivated without sound Jing and Qi. An old proverb says that a sound mind lives in a sound body. When cultivated, Shen will bring peace of mind.
"Jing naturally transforms into Qi, Qi naturally transforms into Shen, and Shen naturally transforms into pure openness, uniting with the cosmic space.” -Master Li
When we develop Jing, we get a large amount of Qi automatically. When we have a large amount of Qi, we will also have strong Shen, and we will become bright and glowing as a holy man.
You can’t really have good shen if you don’t have good jing and qi. These latter two form the foundation from which your shen can shine. This also means that if you have good jing and qi, it will be natural for you to have more shen, though there certainly could be exceptions to this rule.
"All disease and suffering arise out of the imbalances of the Three Treasures, Jing, Qi and Shen." – Ron Teeguarden, M.H.
The Shen represents the forces that shape our personality including mental and spiritual aspects. Shen disturbances generally refer to mental disorders.
Weak shen will lead to a person that is ruled by emotions. They may be angry, sad, depressed, jealous, or filled with worry and anxiety. Its likely that they’ll be driven by the lower needs of food, sex, security, etc. in excessive ways rather than moving onto higher needs and keeping balance.
Another aspect of weak shen would be the disconnected person. Those that are overly robotic or skeptical and those without any spiritual practice (which can take many different forms).
A person with good shen will be a balanced person, mentally and emotionally. They’ll be well situated to be successful in what they do, regardless of what that is.
When these two treasures are in balance, the mind is strong, the spirit is great, the emotions are under control and the body is strong and healthy.