Yin and yang viewed as parts of an oneness that is expressed in the Tao. The term "dualistic-monism" or dialectical monism has been coined in an attempt to express this fruitful paradox of simultaneous unity and duality. Yin and yang can be thought of as complementary (rather than opposing) forces that interact to form a dynamic system in which the whole is greater than the assembled parts. According to this philosophy, everything has both yin and yang aspects (for instance, shadow cannot exist without light). Either of the two major aspects may manifest more strongly in a particular object, depending on the criterion
Taoism principle, seen in all forms change and difference such as the annual season cycles, the landscape, sexual coupling, the formation of both men and women as characters, and sociopolitical history. While almost all Taoist organizations make use of it, one could also regard it as Confucian, Neo-Confucian or pan-Chinese. One can see this symbol as a decorative element on Taoist organization flags and logos, temple floors, or stitched into clerical robes. According to Song dynasty sources, it originated around the 10th century CE. Previously, a tiger and a dragon had symbolized yin and yang. Taoist temples may fly square or