Yin-Yang

including coldness, downward direction, dimness, etc., while the basic properties of yang are like those of fire, including hotness, upward direction, brightness, etc. From this, it can be inferred that anything that has the characteristics of quiescence, coldness, lower position (or downward direction), interior position (or inward direction), dimness, asthenia, inhibition, slowness, or which is substantial, etc., pertains to yin; whereas anything that is moving, hot, in an upper position (or moving in an upward direction), exterior position (or outward), bright, synthetic, excited, rapid, non-substantial etc., belongs to yang.

Since the yin-yang nature of a thing exists only by comparison, and moreover that a thing can be divided infinitely, its yin-yang nature is by no means absolute, but is relative. In some circumstances the two opposites of a thing may change, and so the yin-yang nature of the thing also changes. There exist the conditions of a yin aspect developing within yin, yang within yang, yang complicated with yin, and yin complicated with yang. This concept conforms to objective reality.

The tissues and organs of the human body may pertain either to yin or yang according to their relative locations and functions. Viewing the body as a whole, the trunk surface and the four extremities, being on the exterior, pertain to yang, while the zang-fu organs* are inside the body and are yin. Viewing the body surface and the four extremities alone, the back pertains to yang, while the chest and abdomen pertain to yin; the portion