The Chinese believe that as well as the body being made up of individual organs, they interact with each other on a global or holistic level - a fundamental interconnectedness of all (Twentieth Century Western physics has a parallel with aspects of quantum physics). If a particular organ is sick, never look only at that organ, but at the whole body to find the cause. Flowing throughout the body is what is known as 'Chi' or energy, which runs along a complex series of pathways, known as meridien lines, closely related to the nervous and vascular systems, connecting all parts of the body. The Chi is found at a molecular level, and to find a western parallel, it could be the force that holds the atoms in orbit around each other - electromagnetism.

When the Chi runs throughout the body very strongly, the body is at its best and most efficient. When it is weak, or the meridien lines are blocked at certain points, then the body sickens. The body should be in perfect equilibrium - yin and yang, a balance of aggressive or outward forces, and passive or inward ones. This does not just relate to the physical body, but to the mind as well (many imbalances, and sicknesses stem from the brain, including stress). A number of practices use these principles, including Shiatsu, Acupuncture, and Chi Kung. Chi Kung, older than Tai Chi, is a complex series of breathing excersises which revitalise both body and soul by working on the Chi energy. Tai Chi uses breathing and movement for similar ends, and the two forms are generally practised side by side.