2. The Dao of Dialectics

As has been widely noticed, the Dao of dialectics is one of the great contributions made by Lao Zi that marks a big leap forward in the maturity of Chinese philosophical thought. It is concisely condensed as follows:
"Reversion is the movement of the Dao. Weakness is the function of the Dao." (Ch. 40)
Obviously the Dao of dialectics lies in the movement and function of the Dao itself. "Reversion" (Fan) is a dynamic term. It refers to a kind of interrelation between opposites in one sense, and kind of return to the root known as the unity or union of opposites in another sense. The former reveals the state of being opposite, while the latter reveals the state of transformation of change. The situation may be symbolized by the traditional symbol of Tai Ji ("Great Acme" in literal translation) in which the two forces known as Yin and Yang are always on the move interdependent and interacting at the same time. Lao Zi was extremely observant with regard to the changes that take plan between and within things themselves. This indicates that thing are inclined to reverse to their opposites in a constantly changing process. It is noticeable in both nature and human society that everything is doomed to roll downhill once it reaches the acme As the saying goes: Things that are too lofty fall down easily things that are too white stain easily; songs that are too pretentious have few listeners; reputations that are too high fall short of reality. All these possibilities seem to be in conformity with the Chinese conception of "inevitable reversal of the extreme" (wu ji bi fan).
The statement that "Weakness is the function of the Dao" is a further justification of the foregoing assertion that "Reversion is the movement of the Dao." Lao Zi was preoccupied wit] "keeping to the tender and weak" because he believed that "the tender and weak is bound to conquer the hard and strong." Thu he made frequent use of "water" as a simile when illustrating the potential and overwhelming power of "the tender and weak. Notwithstanding the instructiveness of Lao Zi's dialectical method, one must be highly conscious of its problematic facet that is largely due to his tendency to absolutize the function of "weak ness" by cutting it off from actual and varying circumstances o conditions (Ch. 40).
The Dao of dialectics is also reflected in Lao Zi's notion that "Have-substance (you) brings advantage while have-vacuity (wu) creates utility" (Ch. 11). By "have-vacuity" is meant, for example, the central hole in a wheel, the empty space in a bowl, or the interior vacancy in a room. By "have-substance" is meant something concrete, such as the spokes united around the hub, the clay used to shape the bowl and the doors and windows that are cut out to form a room. Lao Zi reckons that these two aspects are seemingly opposite. However, being counterparts, they help complete each other and therefore remain inseparable and interdependent. What is instructive in this perspective is the fact that it reminds us of the importance of the in concrete dimension of things, which we tend to neglect.

As applied in Tai Chi Chuan, the "water" element remains the major principle to be applied all along Tai Chi Chuan apprenticeship up to real combat confrontation, seldom attacking first but transforming the concept of aggressor/aggressed to "initiator(attack)/reversor(deviate&counterattack).