Lao Zi, with the surname of Lee and the given name of Er, was also called Lao Ran. He lived in the 6th century BC, and was a great philosopher, thinker, educator and the founder of the Taoist school of thought in ancient China.

According to the extant historical documents, Lao Zi was a learned, sharp-eyed, forethoughtful, and eloquent wise man, which might have something to do with his experience as a historiographer in charge of the libraries of the Eastern Zhou Dynasty (770-256BC). He pointed out that it was the severe exploitation of the rulers that caused people to starve. Confucius, the founder of Confucianism, consulted with Lao Zi many times and once compared him to a dragon, which exemplified how enigmatic Lao Zi was.

Lao Zi held that everything was linked with and dependent on one another. Each pair of yes and no, easy and difficult, long and short, etc. was a contrastive unification. If one side didn't exist, there wouldn't be the other. He also asserted that the two opposite sides could be converted. Meanwhile, dissatisfied with the social reality of in-fighting and hard life, he advocated a society of a small country with a small population and no communications with neighboring countries.

The biggest achievement of Lao Zi is his book Daodejing (Classic of the Way and Its Power), and it is said that after finishing this book, Lao Zi was never seen again. Daodejing is actually a 5,000-word philosophical poem in verses, which consists of two parts: Daojing, with an emphasis on philosophy, and Dejing, with an emphasis on politics and military affairs. Daodejing, putting forward metaphysics systematically for the first time to the real formation of Taoist school of thought, plays a key role in the formation of ancient Chinese philosophy. Early in the Western Han Dynasty (206BC-8AD), the ruling class practiced a kind of so-called Huanglao (Emperor Huang and Lao Zi) politics, characterized by Taoist doctrine of governing by doing nothing, and realized a quick economic instauration, known as
Reigns of Wen & Jing (prosperity in the period of Emperor Wen and Emperor Jing) in history.