The Chi of Acupuncture
Before the arrival of Buddhism, chi was conceived as a sort of undifferentiated matter that serves as the basis for all other matter.10 The idea is close to the one of stem cells that can transform themselves into any other kind of particular tissue (bone, blood, nerves, etc.). Chi is the prime matter of the universe, undifferentiated but rich, that transforms itself and particularizes itself as it differentiates itself. For the Chinese, matter is dynamic. It transforms itself and contains the forces that render it dynamic. The yin characterizes one type of force, a particular type of dynamic.
Chinese theories on the relationship between chi and Tao varied. For certain schools of acupuncture, chi is a derivative of the Tao; for others, it is a sort of twin of Tao, and the Tao is not even mentioned. Chi and Tao are not phenomena that the senses can detect. A wise person can only observe what modifies itself on the surface of things and then deduce, from these observations, what forces such as the chi are being activated. Hot and cold, heavy and light, bright and dark, mobile and static, solid and liquid, and so on, allow us to know if it is the aspect of yang or yin that is at play. In other words, chi particularizes itself in creating a particular material dynamic whose contour and properties it is possible to identify.
Some dynamics of chi pass through the meridians, sort of arteries and veins of the chi. As the blood is just one of the fluids of the body, the chi that circulates in the meridians is but one part of the chi of the organism.