Lao Tzu was a Chinese philosopher and founder of the philosophical system of Taoism. He is best known for his book, the Tao Te Ching, a fundamental work of Chinese philosophy and spirituality. He is believed to have lived in the 6th century BCE and is thought to have been a record-keeper at the Zhou dynasty court. His teachings focus on living in harmony with the Tao, or the natural order of the universe.