Lao Tzu is believed to have been a Chinese philosopher (a person who seeks to answer questions about humans and their place in the universe) and the accepted author of the Tao te ching, the main text of Taoist thought. He is considered the father of Chinese Taoism (a philosophy that advocates living a simple life).
The main source of information on Lao Tzu's life is a biography written by the historian Ssu-ma Ch'ien (145–86 B.C.E. ) in his Records of the Historian. By this time a number of traditions or beliefs about the founder of Chinese
Taoism were going around, and Ssu-ma Ch'ien himself was unsure of their authenticity. The biography in fact contains an account of not one but three men called Lao Tzu.
The first Lao Tzu was a man named Li Erh or Li Tan, who came from the village of Ch'üjen in the southern Chinese state of Ch'u. Li Erh served as historian in charge of the official records in the Chinese imperial capital of Loyang. He was a peer of the famous Chinese philosopher Confucius (551–479 B.C.E. ), and he is reported to have given an interview to Confucius when he came to Loyang seeking information on the Chou ritual.
Another man identified as the founder of Taoism was Lao Lai Tzu, who also came from Ch'u. He is said to be a person of the same age as Confucius and is credited with a fifteen-chapter book explaining the teachings of the Taoist school. Nothing more is known about the second Lao Tzu.
According to a third account, the original Lao Tzu lived 129 years after the death of Confucius. This man went by the name of Tan, the historian of Chou. Actually, it is impossible to prove the historical accuracy of any of these accounts. Lao Tzu is not really a person's name and is only a complimentary name meaning "old man." It was common in this period to refer to respected philosophers and teachers with words meaning "old" or "mature." It is possible that a man who assumed the pseudonym (assumed name) Lao Tzu was a historical person, but the term Lao Tzu also was used as a substitute title to the supreme Taoist classic, Tao te ching (Classic of the Way and the Power).
According to Ssu-ma Ch'ien, Lao Tzu had been serving in the Chou capital for a long time. He became unhappy with the dishonest political situation and decided to go into retirement. As he was passing through the Hanku Pass west of Loyang, the gate-keeper stopped him and asked him to write down a book of his teachings. Lao Tzu then composed a book of five thousand sayings in two sections that described the theory of the tao and te. This book was then known as the Tao te ching.
Lao Tzu is frequently associated with the other famous early Chinese thinker, Confucius. There are numerous stories about debates that supposedly took place between these two great philosophers in which Lao Tzu was always the winner. These stories are undoubtedly anti-Confucian publicity circulated by members of the Taoist school, perhaps as early as the fourth century B.C.E.