Taijitu seen in Tripilja culture in Ukraine, displayed in the Ukraine pavilion at the Expo 2010 in Shanghai, China. Also, the interlocking design is found in artifacts of the European Iron Age. While this design appears to become a standard ornamental motif in Iron-Age Celtic culture by the 3rd century BC, found on a wide variety of artifacts, it is not clear what symbolic value was attached to it. Unlike the Chinese symbol, the Celtic yin-yang lack the element of mutual penetration, and the two halves are not always portrayed in different colors. Comparable designs are also found in Etruscan art.
Zhou Dunyi that "the many are ultimately one and the one is ultimate." This was the first 11th-century Chinese text to argue for the inseparability of metaphysics or cosmology and ethics, as well as the first major Chinese text to explore the concept of the taijitu or "yin-yang symbol". It contained his theory of creation, which can be summarized in the following paraphrase of its first section: "In the beginning, there was t'ai chi (taiji) (the great ultimate of being), which was fundamentally identical with wu chi (wuji) (the ultimate of non-being). Because of the abundance of energy within t'ai chi, it