Laozi was roughly contemporary with Confucius or slightly earlier; he founded the Daoist school and is revered as the founder of Daoism. During the Tang Dynasty, Emperor Gaozu Li Yuan, seeking to legitimize his rule, posthumously recognized Laozi as his ancestor and honored him as the "Supreme Mysterious Primordial Emperor," while during Wu Zetian's reign, he was further titled "Supreme Elderly Lord."
His doctrine embodies simple dialectics, profoundly influencing Chinese philosophy, making him a great ancient philosopher and thinker.
Laozi, also known as Lao Dan, is traditionally said to have the surname Li, given name Er, and courtesy name Boyang; his father was the military general Lao Zuo. Laozi was born prematurely, weak in body but with a large head, and because his ears were both big and long, he was named "Dan."
Lao Dan was intelligent and fond of thinking from childhood, mastering all that his teacher Shang Rong had to offer in just three years. Shang Rong said that Zhou's capital was a gathering place for the empire's classics and wise men, and recommended that Lao Dan go there to study. After three years in Zhou, Lao Dan made great progress and was recommended to serve as the curator of the Repository of Archives. The Repository housed the Zhou dynasty's documents, collecting writings and books from across the realm, containing virtually everything. As the manager of the Repository, Lao Dan had the opportunity to read all the books stored there. After another three years, Lao Dan had become renowned far and wide for his vast learning and extensive knowledge. His scholarship deepened and his fame grew; during the Spring and Autumn period, people addressed those with profound knowledge as "Zi" as a sign of respect, and thus Lao Dan was called "Laozi."
Later, Laozi saw that the Zhou royal court had declined, becoming a mere figurehead, with feudal lords refusing to show allegiance and frequently waging wars to compete for supremacy. Unwilling to witness the Zhou court's disgrace, he decided to resign from his official post and travel far away to the west, where he would enlighten the people there. Riding a green ox, he left Luoyi and headed westward.
One morning, he arrived at Hangu Pass. The pass, located in present-day Xin'an County, Henan, was the only route to the west. Here, a narrow path wound between steep cliffs, deep and perilous, like a box, hence the name Hangu Pass (meaning "Box Pass"). The guardian of the pass was Yin Xi, known as Lord Yin, a man of cultivation, learning, and skilled in observing celestial signs. Standing atop the city wall, he suddenly saw a purple mist rising from the east and thought that a sage would pass through the pass that day. So he went out to welcome him. Before long, an old man with a snow-white beard and extraordinary bearing, riding a black ox, slowly approached the pass. Yin Xi had long heard of Laozi's wisdom and recognized him, realizing that Laozi intended to leave. He detained Laozi, insisting that he write something down to leave behind his wisdom, or else he would not let him pass. Laozi had no choice but to agree. Lost in thought, he wrote his wisdom on bamboo slips. A few days later, he completed an essay of about five thousand characters, titled "Laozi," which focused on "the Way" and "Virtue," later known as the "Dao De Jing." It is said that after reading Laozi's essay, Lord Yin was deeply moved and eventually abandoned his post to follow Laozi.
The Tao Te Ching consists of 81 chapters in total, divided into two parts: the upper "Virtue Section" and the lower "Way Section," with the first 37 chapters forming the Virtue Section and chapters 38 through the end forming the Way Section. The Tao Te Ching is a work reflecting Laozi's philosophy, with the Virtue Section placed first and the Way Section second; "Virtue-Way" signifies illuminating virtue to return to the Way and nurturing the Way through virtue, while also embodying moral connotations, aligning with Laozi's original intent of returning to the Way through pure virtue.
Laozi attempted to establish a theory encompassing all things in the universe, stating that "the Dao gives birth to one, one gives birth to two, two gives birth to three, and three gives birth to all things," abstracting the Dao as a universal, all-encompassing objective natural law to explain the evolution of the cosmos. In his view, the Dao is the origin of heaven, earth, and all things, transcending even heaven itself, possessing the eternal significance of "standing alone without change and moving everywhere without exhaustion," a perspective that contains elements of naive materialism.
The book Laozi also contains rich dialectical thought; for example, it holds that all things have two opposing aspects, and that "reversal is the movement of the Dao," meaning these opposites can transform into each other—"the correct becomes the strange, the good becomes the evil," and "misfortune is what fortune depends on, fortune is where misfortune hides." It proposes that the way for opposites to transform is through "abiding in stillness," with "being and non-being giving rise to each other," where "non-being" is the foundation—"all things under heaven are born of being, and being is born of non-being"—so everything in the world is a unity of "being" and "non-being."
Thus, Laozi advocated "non-action" (wu wei) and promoted "governing through non-action" in politics. Laozi's "non-action" does not mean doing nothing, but rather following the natural course of things, refraining from reckless or arbitrary action, and avoiding doing whatever one pleases—subjectively "non-acting" by not aiming for personal gain, thereby achieving objective "action" (you wei) that better realizes benefits.
Furthermore, the Tao Te Ching embodies many people-oriented ideas, such as: "The Way of Heaven reduces the excessive to supplement the insufficient; the way of man is the opposite—it reduces the insufficient to offer to the excessive"; "The people despise death because their rulers seek to enrich their own lives"; "If the people are not afraid of death, how can they be threatened with it?"
Although the Tao Te Ching contains only five thousand characters, it has had a profound influence on the development of Chinese philosophy, with many idioms such as "knowing oneself," "a good beginning makes a good ending," and "a journey of a thousand miles begins with a single step" having been passed down through the ages.