Before examining how the notion of oneness of yin and yang characterizes our cognition in detail, however, it is helpful to delineate three issues: a) differences between Taoist philosophy and religion, b) divergences between Taoist philosophy and Confucianism, and c) the impact of Taoist philosophy on Zen Buddhism. All of them are important aspects of Eastern tradition, but Taoist philosophy (including the notion of unity of opposites) is unique in influencing psychology.
First, it should be noted that although Taoist philosophy (道学 or 道家) influenced the formation of Taoist religion （道教）and the two are frequently perceived as synonymous, their contents and practices are not exactly the same. Taoist philosophy reached maturity around 500--400 BC. The Taoist religion, which integrated a belief in immortality, meditation, and the practice of alchemy with some notions of Taoist philosophy, was formed in China around 100-200 BC. In addition, Taoist philosophy searches and recognizes "Tao" or universal patterns, but Taoist religion enrolls some Chinese folk gods.
Taoist philosophy represents a much broader scholarly system than Taoist religion. Nevertheless, Taoist religion has amassed its distinctive cultural contributions. For example, all today's tai chi schools originated from the Temple in Wudang Mountain, where Taoist priests have been practicing the earliest form of tai chi for a millennium. If you remember the movie "Crouching Tiger and Hidden Dragon," the last episode was filmed on the top of the mountain.
Second, Taoism and Confucianism embody the major native philosophical traditions that have shaped and permeated Chinese culture-and those Asian cultures affected by China such as Japan, Korea, and Vietnam-for more than two millennia. However, the unique content of Taoist philosophy makes it more suitable than Confucianism for examining psychological issues. For example, Confucianism emphasizes tradition, ethics, social order, and social responsibility. In contrast, Taoism advocates the importance of aligning life to the rhythm and the patterns of evolving nature, the unity of yin and yang in all nature, and the interdependence and balance among all entities.
Third, Taoist philosophy was also instrumental in creating Zen (Chan，禅) Buddhism in China by modifying Buddhist ideas introduced from India between the second to the sixth centuries. As Alan Watts commented, the humanism and naturalism in Zen Buddhism, its origin, and its development all reflected the view of life in the philosophy of the Tao.
In short, because of its insight into the way of the universe and human life, philosophical Taoism has profoundly influenced Eastern sciences, healing arts, literature, and the understanding of the mind and psychological activities.
.....To be continued.
These serials are based on:
Sun, K. (2009). Using Taoist principle of the unity of opposites to explain conflict and peace.
The Humanistic Psychologist, 37, 271-286.
