"What is Loki without Thor?" In Chinese philosophy, yin and yang, are concepts used to describe how apparently opposite or contrary forces are actually complementary, interconnected and interdependent in the natural world, and how they give rise to each other as they interrelate to one another. Many tangible dualities (such as light and dark, hot and cold, life and death, sun and moon) are thought of as physical manifestations of the duality of yin and yang. 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. 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 of the observation.