Lao Zi, also Li Dan by name, live in late Spring and Autumn Period(585 BC �C500 BC). He was from the state of Chu and once was the librarian and archivist of the royal court of Zhou Dynasty. He was a knowledgeable person that even the great Confucius had once consulted him on things that he couldn't understand as a young man. Lao Zi authored the book Dao De Jing, the classic for Daoism.

"Dao" is the metaphysical core of Lao Zi's philosophy, derives from his perspicacious generalization from human life, society and politics. "Dao" in its original meaning, is a road that leads to all directions. Lao Zi attributed a new meaning to it. By the word Dao, he means it is the basic elements or root that can give birth to all things, meanwhile, it  is  independent  of all other things. 

Lao Zi believes that things are established in their antithetical relationship. We can see the positive side of the things and at the same time, we should also see the negative side of them. When the opposite side develops to the extreme, it will have to turn to the other side. When things reach their prime, they have to decline.

He also believed that an accumulation of certain things could eventually develop into something else when it reached certain point. Quantity changes could accumulated to quality changes. For example, a small seed could grow into a tall tree. He encouraged people that continued efforts will eventually bring about success.

Lao Zi was against wars and over taxations from the ruling class. His utopia is: a small state with a small population. There are no use for weapons. Everything would be so convenient that people could go about their life without the need for carriages and boats. People eat well, dress finely. Two states could be very near that each could hear the noise from the other side, but never in their life should they have the necessity of exchange with each other. There's not even the need for writings.

Lao Zi's philosophy later exerted great influence on later philosophers.