This is a sentence from Sima Qian in his "Report to Ren An". Research, study, explore, discuss, think. Heaven, the way of heaven, laws, nature, destiny, destiny. People, personnel, society, life, dynasty. Term, edge, connection, correlation, between each other. Tong, straighten out, understand, understand. Change, change, evolution, migration, replacement.

Overview: Research and explore the relationship between the unity of opposites between natural laws and social laws, rationalize and understand the changes and migrations from ancient times to the present, and achieve your own independent and perfect theoretical writings.