Who used the yin yang monad?

The yin yang monad is often associated with Taoist philosophy and Chinese cosmology, particularly in the works of philosophers like Laozi and Zhuangzi. It represents the duality and interconnectedness of opposing forces, such as light and dark, and is a fundamental concept in understanding balance and harmony in the universe. The symbol itself, depicting the interplay of yin (the dark, passive force) and yang (the light, active force), has been widely used in various cultural and philosophical contexts to illustrate these ideas.