Principles of Yin and Yang
The inter-transformation of Yin and Yang.
In nature: The day changes into the night, the night changes again into the day. The morning corresponds to the Yang within Yang which is increasing up to midday, which is the utmost Yang. Starting from midday Yang decreases and Yin increases, until Yin has reached its maximum at midnight. The Yang again increases from midnight and likewise Yin decreases. The point of reversal does not take place by chance but rather if one extreme has reached its maximum and the other extreme has reached its minimum. This cycle can be observed in nature in a variety of different forms. For example: The water of the seas and rivers (Yin) evaporates and rises as steam (Yang) into the atmosphere to again fall on the earth in the form of rain (Yin). In human beings: If we catch a common cold, a healthy organism naturally responds with fever. If Cold (Yin) penetrates the organism, the body produces Heat (Yang), in order to expel the Cold. Active sport increases Heat (Yang) in the body. In order to maintain the body temperature, the body reacts with perspiration. Perspiration is Cold from evaporation (Yin) which is used to cool the Heat. Inner Dryness can cause a demand for "moistening food". But if food, which produces cloudy Body Fluids is consumed, Dampness can develop. Because Yin nourishes Yang, Yang Deficiency can be caused by Yin Deficiency (for example burnout-syndrome) and vice versa. One can often observe Heat (Yang) as a reaction to Cold (Yin), or Cold as a reaction to Heat. Clinically, this can be particularly important, because the cause of a Heat disease can be Cold. If Heat is dispelled in such a case, the underlying Cold-symptoms will appear.