How Was Yin and Yang Formed?
In ancient Chinese philosophy, 
yin and yang is a fundamental cosmological view and methodology used to explain various phenomena and laws of the natural world. The theory of yin and yang originated from ancient people's observations of the natural world, in particular their intuitive perception of the light and dark sides of objects under sunlight.
In its most primitive form, yang represents brightness, warmth, positivity, initiative, extroversion and other characteristics, and is often associated with the sun, daytime, fire, and masculinity. Yin, on the other hand, represents darkness, coldness, negativity, passivity, introversion and other characteristics, and is often associated with the moon, nighttime, water, and femininity.
The formation of yin and yang can be traced back to the theory of the eight trigrams in the I Ching, in which the trigrams Qian and Kun symbolize heaven and earth, respectively. These two forces are considered to be the basis of the generation and change of all things in the universe. Their interaction, restriction and transformation form the diversity and dynamic balance of all things in the world.
With the development of philosophy, the theory of yin and yang has been widely used in traditional Chinese medicine, feng shui, martial arts, divination and other fields, becoming an important tool for understanding and regulating various life activities and social phenomena. The yin and yang thinking emphasizes the unity of opposites, believing that everything in the universe is composed of the two relative attributes of yin and yang, which are interdependent, interact with each other and transform each other. This concept embodies the dialectical thinking and holistic concept of ancient Chinese philosophy.
