 The Green Sun Assembly was held at the end of the first period, the Red Sun Assembly in the second one and the White Sun Assembly will be held in the third one.The doctrine of the Three Ages is discussed in Neo-Confucian and New Confucian teachings, the "Gongyang Commentary" and the "Datong shu" of Kang Youwei.The Confucian interpretation is comparable to the doctrine of the Spirit in Hegelian thought.