The term '-TZU' is associated with two famous Chinese philosophers, Shih and Lao. Shih, also known as Confucius, was a Chinese teacher, editor, politician, and philosopher of the 6th century BCE. He is credited with writing the Five Classics, which are some of the most important books in Chinese history. Lao, also known as Laozi, was an ancient Chinese philosopher and writer who is believed to have lived in the 6th century BCE. He is the author of the Tao Te Ching, a book of wisdom and philosophy that has been influential in Chinese culture for centuries.