Three basic themes underlie this concept. First, it is the fabric of all
existence, as mind/body, matter/energy, space/time, and similar
dichotomies. Second, it is the pattern of change, the balancing waxing
and waning of all things. Finally, it is the constant, dynamic balance
of all things, where excesses naturally correct themselves.
The earliest Chinese characters for yin and yang are found on “oracle
bones” in the fourteenth century BC. In these inscriptions, they were
descriptions of the climate, sunlight during the day (yang), and a lack
of sunlight at night (yin). Later these ideas became associated with the
division between the sun and moon, and heaven (light) and earth (dark).
Over time, they began include the movement of force (chi or qi)
between opposites and the physical forms of complementary opposites in
nature, such as men and women.
During Sun Tzu's era, the fifth and sixth century BC, the Yinyang School of
philosophy was one of the six primary schools mentioned by the historian
Sima Qian. It included a number of associated sciences, such as astronomy, numbers,
fortune telling, and, most importantly, wuxing,
the “five phases” based on
the five elements, and zhuguai, tortoise-shell divination
that became associated with the Bagua. All these ideas can be traced back to the I Ching,
the source work of Chinese culture.
The Zuo Zhuan (Chinese: 左傳) is the earliest Chinese work of
narrative history, covering the period from the eighth to fifth centuries
BC, as a commentary to the Spring and Autumn Annals, which is the period in which Sun
Tzu lived. It defines the yin and yang as the first two of six heavenly
forces:
There are six heavenly influences [qi] which descend and produce the
five tastes, go forth in the five colors, and are verified in the five
notes; but when they are in excess, they produce the six diseases. Those
six influences are denominated the yin, the yang, wind, rain, obscurity,
and brightness. In their separation, they form the four seasons; in
their order, they form the five (elementary) terms. When any of them is
in excess, they ensure calamity. An excess of the yin leads to diseases
of cold; of the yang, to diseases of heat. (Legge 1994: 580)
Anyone familiar with Sun Tzu's text will note the many parallels here
with his work. There is also a very similar pattern of numeric
associations. Most of these many numeric patterns in Sun Tzu have
complementary opposites embedded within them. The five key factors or
elements are two sets of complementary opposites around a core; the six
field positions are two extremes in three dimensions; and so on. This
concept is critical in understanding Sun Tzu's work.
Sun Tzu taught that the natural balance in competition is maintained by
these underlying opposing forces that create stable systems. We succeed
in competition by leveraging these forces rather than fighting them.
Interestingly enough, Sun Tzu used the specific terms yin and
yang very narrowly in his work. They describe only specific
conditions of the ground. Instead, he
preferred to discuss the general concept that we now call "yin and yang"
in its specific tangible forms: birth/death,
ground/climate, command/methods, defense/attack, nation/army,
king/general, survival/destruction, and so on. When he discussed the
conceptual movement of energy between two complementary opposites he
used the ideas of emptiness and fullness, which we also
translate as strength and weakness.
In modern terms, we can express this idea of complementary opposites in
a variety of ways. When we say that nature abhors a vacuum, what goes up
must go down, and that opposites attract, we are expressing the
classical idea. In physics, we talk about positive and negative charges.
In statistics, we talk about variation and regression to the mean. In
economics, we talk about supply and demand. All these ideas and
more are all part of the generic relationships of complementary
opposites that are the base of classical front-line strategy.
