Lao-tzu was a philosopher of ancient China, and is a central figure in Taoism. Lao-tzu literally means "old master", and is generally considered honorific. He is revered as a deity in most religious forms of Taoism. Taishang Laojun is a title for Lao-tzu in the Taoist religion, which refers to him as "One of the Three Pure Ones".
Lao-tzu lived in the 6th century BC, a slightly older contemporary of Confucius. The specific date of birth of Lao Tzu is unknown, but scholars place his birth between 600 and 300 B.C. The earliest reliable reference to Lao-tzu is found in

the “Records of the Grand Historian” (“Shi Ji”) by Chinese historian Sima Qian, who concluded three stories. The first one tells that Lao-tzu was a contemporary of Confucius (551–479 BC). His surname was Li, and his personal name was Er or Dan. He was an official in the imperial archives, and wrote a book in two parts before departing to the West. The second story shows that Lao-tzu was Lao Lao-tzu, also a contemporary of Confucius, who wrote a book in 15 parts. The third story tells that Lao-tzu was the Grand Historian and astrologer Lao Dan, who lived during the reign (384–362 BC) of Duke Xian of Qin.
According to popular traditional biographies, he worked as the Keeper of the Archives for the royal court of Zhou. This reportedly allowed him broad access to the works of the Yellow Emperor and other classics of the time. It was said that Lao-tzu married and had a son named Zong, who became a celebrated soldier. A large number of people trace their lineage back to Lao-tzu, as the emperors of the Tang Dynasty did.
Lao-tzu never opened a formal school, but he nonetheless attracted a large number of students and loyal disciples. There are numerous variations of a story depicting Confucius consulting Lao-tzu about rituals.Lao Tzu’s wise counsel attracted followers, but he refused to set his ideas down in writing. He believed that written words might solidify into formal dogma. Lao Tzu wanted his philosophy to remain a natural way to live life with goodness, serenity and respect. Lao Tzu laid down no rigid code of behavior. He believed a person’s conduct should be governed by instinct and conscience.

Tao Te Ching

“Tao Te Ching” was written by Lao-tzu around the 6th century BC. “Tao” means the way of all life, This term, which was variously used by other Chinese philosophers, including Confucius, Mencius, Mozi, and Hanfeizi, has special meaning within the context of Taoism, where it implies the essential, unnamable process of the universe. “Te” basically means “virtue” in the sense of “personal character”, “inner strength”, or “integrity”. “Ching” refers to classic or canon.

“Tao Te Ching” is a short text of around 5,000 Chinese characters in 81 brief chapters. The topics range from political advices for rulers to practical wisdom for people. There are some evidences that the chapter divisions were later additions for commentary, or as aids to rote memorization, and that the original text was more fluidly organized. It has two parts, the Tao Ching from Chapter 1 to 37 and the Te Ching from Chapter 38 to 81. The ideas are singular and the style poetic. The written style is laconic, has few grammatical particles, and encourages varied, even contradictory interpretations.

“The Way that can be told of is not an unvarying way. The names that can be named are not unvarying names.” These famous first lines of the Tao Te Ching state that the Tao is ineffable, nameless, going beyond distinctions, and transcending language. In Lao-tzu's Qingjing Jing he clarified the term Tao was nominated as he was trying to describe a state of existence before it happened and before time or space. Way or path happened to be the side meaning of Tao, ineffability would be just poetic. This is the Chinese creation myth from the primordial Tao.
“It was when intelligence and knowledge appeared that the Great Artifice began.”“The pursuit of learning is to increase day after day and the pursuit of Tao is to decrease day after day.” The Tao Te Ching praises self-gained knowledge with emphasis on that knowledge being gained with humility. When what one person has experienced is put into words and transmitted to others, so doing risks giving unwarranted status to what inevitably must have had a subjective tinge. Moreover, it will be subjected to another layer of interpretation and subjectivity when read and learned by others. This kind of knowledge, like desire, should be diminished.
“Tao Te Ching” was a suite of variations on the “Powers of Nothingness”. This resonates with the Buddhist Shunyata philosophy of “form is emptiness, emptiness is form”. Emptiness can mean having no fixed preconceptions, preferences, intentions, or agenda. “The Sage has no heart of his own. He uses the heart of the people as his heart.”From a ruler's point of view, it is a laissez-faire approach. Looking at a traditional Chinese Landscape, one can understand how emptiness and the unpainted have the power of animating the trees, mountains, and rivers it surrounds.
Another theme of “Tao Te Ching” is the eternal return. There is a contrast between the rigidity of death and the weakness of life. “When he is born, man is soft and weak; in death he becomes stiff and hard. The ten thousand creatures and all plants and trees while they are alive are supple and soft, but when dead they become brittle and dry.” This is returning to the beginning of things, or to one's own childhood.
The “Tao Te Ching” focuses upon the beginnings of society, and describes a golden age in the past. Human problems arose from the “invention” of culture and civilization. In this idealized past, “the people should have no use for any form of writing save knotted ropes, should be contented with their food, pleased with their clothing, satisfied with their homes, should take pleasure in their rustic tasks”.
“Tao Te Ching” contains a good summary of different calligraphies. The Chinese characters in the original versions were probably written in Zhuan Shu (seal script), while later versions were written in Li Shu (clerical script) and Kai Shu (regular script) styles.

Wu Wei is a central concept in Taoism. The practice and efficacy of Wu Wei are fundamental in Taoist thought. The literal meaning of Wu Wei is “without action”. In ancient Taoist texts, Wu Wei is associated with water through its yielding nature. Water is soft and weak, but it can move earth and carve stone. Taoist philosophy proposes that the universe works harmoniously according to its own ways. When someone exerts his will against the world, he disrupts that harmony. Taoism does not identify man's will as the root problem. Rather, it asserts that man must place his will in harmony with the natural universe.

Pu

Pu means “uncarved block”, “unhewn log”, or “simplicity”. It is a metaphor for the state of Wu Wei and the principle of Jian (frugality). It represents a passive state of receptiveness. Pu is usually seen as keeping oneself in the primordial state of Tao. It is believed to be the true nature of the mind, unburdened by knowledge or experiences.

Pu is a symbol for a state of pure potential and perception without prejudice. In this state, Taoists believe everything is seen as it is, without preconceptions or illusion. In the state of Pu, there is no right or wrong, beautiful or ugly. There is only pure experience, or awareness, free from learned labels and definitions. It is this state of being that is the goal of following Wu Wei.

Spirituality
Taoists believe that man is a microcosm for the universe. The body ties directly into the Chinese five elements. The five organs correlate with the five elements, the five directions and the seasons. Like the Hermetic maxim of "as above, so below", Taoism posits that human beings may gain knowledge of the universe by understanding himself.
In Taoism, various rituals, exercises, and substances are said to positively affect one's physical and mental health. They are also intended to align one’s spiritually with cosmic forces, or enable ecstatic spiritual journeys. These concepts are basic to Taoism in its elite forms. Internal alchemy and various spiritual practices are used by some Taoists to improve health and extend life, theoretically even to the point of physical immortality.