Yin and yang
Philosophical concept of dualism in Chinese philosophy, traditional medicine, fengshui, and protoscience, opposing solar/masculine/active/warm yang with lunar/feminine/passive/cool yin
Yin and yang, also yinyang or yin-yang, is a concept that originated in Chinese philosophy, describing an opposite but interconnected, self-perpetuating cycle. Yin and yang can be thought of as complementary and at the same time opposing forces that interact to form a dynamic system in which the whole is greater than the assembled parts and the parts are important for cohesion of the whole. Wikipedia