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Yin and Yang

According to ancient Chinese philosophy, the dual principles of nature. Yin signifies earth, passive, negative, female, yielding, weak, or dark; yang signifies heaven, active, positive, male, strong, or light. These principles are manifest throughout nature and in the human body. They relate to mental, physical, and spiritual structure and are affected by food, drink, action, and inaction. The balance of yin and yang in the individual, nature, and the cosmos is symbolized by a circle separated by an "S" shape, one half of the circle dark and the other light. This has something in common with the ancient Greek alchemical symbol of a serpent or dragon eating its tail, known as Ouroboros.

The yin-yang symbol represents unity and duality, a universal dual monism. It is also inherent in the ancient Chinese system of divination of the I Ching (Book of Changes). It is basic to the teachings of Taoism, as embodied in the classic work Tao-te-Ching (Book of the Right Way) of the philosopher Lao Tzu.

In modern times, the yin and yang principles are a vital part of the revived system of diet known as macrobiotics, where health and mental and spiritual balance are developed by the correct proportions of yin and yang foods, properly prepared.