Laozi, also spelled Lao Tzu, is an ancient Chinese philosopher and writer who is traditionally considered the author of the "Tao Te Ching" and the founder of philosophical Taoism. His name translates to "Old Master" or "Old Teacher." Laozi is a semi-legendary figure, and his historical existence is debated; however, he is conventionally dated to the 6th century BCE. According to legend, he was a contemporary of Confucius. The "Tao Te Ching" is a concise and profound text that lays out the principles of Taoism, emphasizing the concepts of naturalness, simplicity, and harmony with the Tao, which can be roughly understood as the ultimate principle underlying the universe. Laozi's teachings have had a significant influence on Chinese philosophy, religion, and culture, and his ideas have spread to become foundational in various Eastern spiritual and philosophical traditions.