By Marc Ryan
Chinese Medical theory, though scientific in its own right, is
built on a foundation of ancient philosophical thought. Many of these ideas are
based on observations of natural phenomena and are the reason why Traditional
Chinese Medicine (TCM ) has remained a truly holistic approach to health and
The Theory of Yin and Yang is one such philosophy. It is said
to date back nearly 6,000 years to the third or fourth millennium B.C. and is
attributed to an enlightened philosopher named Fu Shi (also credited with
creating the I-Ching or Book of Changes). The basic premise of yin and yang is
the notion that the only constant factor in natural phenomena is universal
change. In other words, nothing remains the same; no disease, no condition, no
emotion, no treatment or diagnosis, absolutely everything is in a constant state
of flux and, therefore, subject to the laws of change.
Yin and Yang are metaphorical images used to express these
constantly transforming interactions. They have no fixed, precise definition.
Rather, they describe two broad categories of complementary concepts which
include the relationships of positive and negative, dynamic and inert, creative
and destructive, gross and subtle, and kinetic and potential. This is quite
similar to the notion of dialectics as expressed in Western philosophy. Within
dialectics the whole is the sum of its parts and in turn part of the sum of a
greater whole. As these various components interact, things become their
opposites; i.e., variables become constants, causes become effects, and the
process of creation leads to destruction. Furthermore, this idea is demonstrated
in modern physics where sub-atomic interactions are the result of ever shifting
polarities and constantly vacillating magnetic attractions and repulsions.
The entire universe may be viewed as the interplay and
alternation of yin and yang. Originally the Chinese characters for yin
represented the moon and yang represented the sun. Gradually these terms were
broadened to include yin as night and yang as day, yin as winter and yang as
summer, and yin as female and yang as male. In fact, there is nothing which
cannot be viewed from the standpoint of yin and yang.
Yin is that which maintains and endures, it is nourishing and
supports growth and development as well as being something contracting and
moving inward. It also includes the following:
Yang is that which is creative and generating, it develops and
expands; it is dynamic and full of movement. It also includes the following:
It is important to remember that yin and yang are not static
concepts and that they are constantly influencing and determining one another.
There is always some measure of yin within yang and vice versa. To use the
analogy of a hillside; during the day the sunlit side of the hill is yang within
yang, while the shaded side is yin within yang. Conversely, at night the moonlit
side of the hill is yang within yin while the dark side of the hill is yin
within yin. In this fluid model it must be understood that neither yin nor yang
can ever exist without the other. In fact, extreme yin will engender yang, an
example of this can been seen in the popular expression "the darkest hour is
right before the dawn". Naturally, the opposite is also true.
These types of relationships become significant when they
impact the body's anatomy and physiology and it is precisely these designations
that are used in the diagnosis of imbalances in TCM. For a TCM practitioner, the
name of the disease is of secondary importance. The primary key to the proper
diagnosis of syndromes is the identification of the condition in terms of yin or
yang. In order to understand what this means let us examine these concepts in
the context of human life.
Beginning at conception the sperm, which is yang, unites with
the yin ovum and a new life is formed. As that life develops and progresses the
energetic stages of youth are yang; whereas the later years are yin as life
slows and becomes more deliberate. Each stage is also relative to the others and
contains a measure of both yin and yang, just as the aforementioned hillside is
an expression of yin within yang, etc. For example, the quick growth of early
childhood is yang within yang and the transition from middle age to old age is
yin within yang.
We can also see this philosophy expressed in everyday life. In
respiration, the expansion of inhalation is yang while the emptiness which
results from exhalation is yin. In digestion, the yin substance of food is
transformed by the metabolic activity of yang. It is then converted into Qi
(yang) and Blood (yin). Qi and Blood interact with one another using this
paradigm. Qi moves Blood, yet Blood is thought to be the "mother" or source of
Qi. Within the body yin is expressed as the material basis, the tissue and
substance without which the transformation of yang would not be possible.
The physical body itself expresses this model. The lower part
of the body which connects to the earth is yin while the upper body and
extremities are yang and free to move. The front, which can easily be protected,
is yin while the exposed back is yang. The internal organs, which are enclosed
and protected, are yin relative to the surface of skin and muscle which are
yang. In addition, the internal organs can be further differentiated into fu
(yang), which are the "hollow" organs that are involved with digestion and
elimination, and zang (yin) which are involved in assimilation and
storage. Each zang has a corresponding fu organ which it is paired
with and while these connections are not recognized in Western medical terms,
they are often utilized in the treatment of disease in TCM.
Finally, disease and disease progression can be viewed using
this paradigm. If the body's yang is weak it will be unable to ward off the
invasion of a pathogen. If the yin is weak there will not be enough nourishment
and support for the yang and the result will be the same. Expressed in other
terms, without the substance, the active immune system is weakened and without
activity the substance becomes vulnerable. Therefore, if yin is deficient over
time then yang also becomes deficient and vice versa. Not only do yin and yang
balance each other, they mutually generate one another. It is precisely this
balance that the TCM practitioner uses various treatment strategies to restore.
The idea is to reestablish the body's innate ability to maintain health and
defend itself from disease.
The nature and progression of disease can also be understood
using this pattern. When a disease develops rapidly, it is in the acute or yang
stage. As it progresses and becomes more chronic, thus it enters the yin stage.
Usually, acute diseases affect the surface or superficial aspects of the body
while chronic diseases have already overwhelmed the body's defenses and gone
deeper into the interior. In addition, regardless of location or duration,
disease can be classified by its affects. Extreme, severe symptoms are
considered excess and are consequently yang. In contrast, mild or diffuse
symptoms accompanied by weakness are considered deficient and are therefore yin.
With regard to diagnosis, that which is internal, cold, deficient or chronic is
considered yin. That which is external, hot, excess or acute is considered yin.
When conflicting signs are present it usually points to a more complex condition
and the TCM practitioner must evaluate all the symptoms together to determine
the appropriate treatment strategy.
In summary, it should be evident that the designations of yin
and yang are universal and extend into every aspect of life. Because of its
ubiquity, this theory is a very useful tool for understanding natural phenomena
and therefore can be an indispensable diagnostic aid. While this is an ancient
paradigm it is not primitive and though simple it can be developed into
surprising complexity. The only limitation of the application of this universal
truth is one's own perception and imagination.
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Between Heaven and Earth, A Guide to Chinese Medicine
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Analysis of Chinese Characters by
G.D. Wilder and J.H. Ingram, Dover Publications, Inc. New York 1974
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