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
Yin and yang with fire, sky, the sun, masculinity and daytime. The yin-yang symbol, having no "officially standardized" rendition, has been the basis of much artistic variation, most of it "frivolous" (that is, "merely" artistic, with no philosophical/mystical meaning, e.g., tattoos). Yin and yang also applies to the human body. In traditional Chinese medicine good health is directly related to the balance between yin and yang qualities within oneself. If yin and yang become unbalanced, one of the qualities is considered deficient or has vacuity. In the "I Ching", originally a divination manual of the Western Zhou period (c. 1000–750 BC), yin and