According to ancient Chinese philosophy, life is the result of a harmonious counterposition between two opposing forces, yin and yang, which in their interaction, in perpetual motion, make up the “essential” energy.
Closely linked to these two counterposed forces is the theory that all phenomena are related, according to their nature, function and form, to one of the five elements: water, fire, earth, metal and water.
Vital functions and pairs of organs are matched with these five elements.