Excerpt taken from "The Dao of Herbs" by Ron Teeguarden in Qi: The Journal of Traditional Eastern Health and Fitness.
The Principle of Yin and Yang
The "great principle" of yin and yang is a fundamental concept in Chinese philosophy and in the Oriental health care system. The great principle of yin and yang was developed more than 3,000 years ago by great sages and scholars.
Yin and yang are the two opposing components of one integrated whole. These two opposing forces are totally interdependent, interacting constantly so as to maintain the normality and integrity of the whole. Each in turn tends to dominate over the other, but no total dominance is permanent.
No matter how dominating one side appears, eventually the other will take its turn as the dominant force. This interplay of opposing forces establishes the basis of all existence and all change.
The law of yin and yang describes the innately dynamic, cyclical, bipolar, pulsing, rhythmic nature of everything in the universe. It is a very simple concept to grasp, although many people find it foreign and difficult at first. To some degree it may be understood intellectually, but fundamentally it must be grasped intuitively. The universe expands and contracts. Light and sound move in waves that are pulsing. The earth turns on its axis resulting in a multitude of rhythmic manifestations here on earth. Human sleeping/waking cycles, seasonal changes and the millions of microscopic cycles that support these daily and seasonal changes are the result of the larger (macroscopic) cycles in our solar system, galaxy and super-galactic systems.
Within our bodies, our hearts beat, our lungs inhale and exhale, our glands secrete hormones, and our bowels and bladders excrete waste rhythmically. Our eyes each dominate for several minutes at a time, rhythmically. Indeed, virtually every human function follows rhythmic patterns. These rhythms are described and explained by the law of yin and yang.
What are these forces called yin and yang? Yin is defined as that part of a cycle or process in which energy is being accumulated, assimilated and stored for later use. Yang is defined as that part of a cycle or process in which energy is being expended in order to create a manifest action. Thus yin is often associated with rest, receptivity and quietude, while yang is associated with action, creativity and movement. But yin should not be thought of as the absence of yang. Nor should it be automatically associated with weakness. Yin is, in fact, the very substance of life, and it is absolutely essential to all functioning. Yang on the other hand is the functional, active aspect of any process and is also essential to life. Yin and yang are relative concepts, and they always exist together. They are different aspects of the same thing or process, two sides of the same coin.
The relationship of yin and yang is never static. Though the two forces are actually acting in harmony with one another, they are also always competing with one another for dominance. First one dominates, then the other in its appropriate time. Under normal circumstances, the interaction of the two forces will remain within well-defined limits. Yin provides sustenance for the yang and the yang protects the yin.
Neither yin nor yang will normally go to such an extreme that its opposing force cannot recover. However, if for some reason yin or yang exceeds the limits normally inherent in the system, the self-regulatory mechanism breaks down and crisis ensues, perhaps leading to the breakdown of the system. In human physiology, such a breakdown is synonymous with illness or even death.
Health is dependent upon the maintenance of the correct balance of yin and yang forces in the body and psyche. Neither yin nor yang should increase or decrease beyond normal limits. It is believed possible, through the regular consumption of Chinese tonic herbs, to help the body-mind maintain its self-regulatory capacity, assuring optimum functioning and radiant health. This is the very basis of Chinese tonic herbalism.
The Yin and Yang of People
Our personalities reflect yin and yang. A person who is shy and inward would be said to have a yin personality. An outgoing, assertive or aggressive individual would be said to be more yang. Of course, our personalities change throughout the day and over time. We all go through yin phases and yang phases.
Our personal relationships also manifest the principle of yin and yang. Sometimes we dominate another individual and sometimes we are the dominated. Sometimes we are the giver and sometimes we are the receiver. Giving and receiving in life are but a reflection of the universal law of yin and yang.
Yin and yang is a concept of relativity and each person must be looked at relatively. An aggressive person with a hot temper would be considered to be of a yang nature, irrespective of gender. A cold, inward, passive person would be considered relatively yin, irrespective of gender. A person who is dry (yang) will need to increase their fluids and blood (yin) and a person who has cold extremities will need to invigorate their circulation and metabolism by increasing yang in order to establish a healthy, balanced physiology.
Herbs and the Regulation of Yin and Yang
In Chinese tonic herbalism, we utilize the law of yin and yang constantly. Tonic herbs are categorized according to yin and yang. It is the attempt of tonic herbalism to provide yin and yang energy in an appropriate balance so that the individual eventually attains a proper dynamic balance and thus attains radiant health. Thus it is important to discern which balance of yin and yang herbs is appropriate. A person who shows signs of yin deficiency will do well to take more yin herbs while a person who shows signs of yang deficiency should take more yang herbs.
It is our belief that, since yin and yang are always both necessary, both yin and yang herbs should be consumed by everybody. Since yin is by definition cooling, moistening and relaxing, yin deficiency is often characterized by hot conditions, hot feelings, dryness and agitation. Yang, on the other hand, is warming, drying and invigorating. Therefore yang deficiency is characterized by cold feelings and conditions, excessive moistness and a lack of vitality (fatigue).
Chinese tonic herbalism is an adaptogenic system. This relates to the concept that the body-mind is naturally and innately self-regulatory. Human neurological and endocrine functions have evolved over millions of years as the primary human regulatory systems designed by nature to maintain homeostasis (functional balance), even under an enormous variety of stressful conditions, thus allowing the whole system to survive and even thrive.
The goal of tonic herbalism is to help the tonic herbs user to establish a harmony of body, mind and spirit which can result in a new level of well-being, a new level of health and happiness that forms the foundation for a creative, successful life, as well as for true spiritual discovery, growth and, possibly, eventual mastery and enlightenment.
The Chinese tonic herbs appear to help these fundamental regulatory systems in maintaining optimal functioning and provide increased vitality in carrying out their roles efficiently and accurately. Furthermore, adaptogenic herbs and formulations appear to expand the range of adaptability, thus increasing the amount of stress an individual can sustain before breaking down.
This adaptogenic quality is the basis of the Daoist concept of "radiant health," which is generally defined as "health beyond danger." If one has increased adaptive capacity, it is possible to survive or even thrive under stressful conditions that other: more common, less well-nourished individuals might not.
When we have mastered the principle of yin and yang, we have mastered the art of living.