Laozi, traditionally identified as Li Er, is credited as the founder of philosophical Taoism and reputed author of the Tao Te Ching. Classical sources place his birth in the state of Chu during the Spring and Autumn Period, circa 6th century BCE. Modern scholars debate his historicity, with some placing him in the 4th century BCE Warring States period. The name Laozi, meaning "Old Master," may represent an archetype rather than a single individual.