shì shì zhī liú, xiāng jī shǐ rán 事势之流，相激使然
The Flow of Events Is Caused by Interactions.
Changes in trends or situations arise from the clashes and stimuli of factors and forces. This was an explanation of history proposed by the famous ancient Chinese historian Sima Qian (145 or 135?-? BC). “Events” were the basic trends or situations in the world; their “flow” was how they changed over time like flowing rivers. Sima Qian felt that while history was composed of the stories of people, it could not be changed by the will of any one person or persons. Rather, the outcome of the flow of events was basically determined by the clash or stimulus of various factors and forces involved in the process. This embodies ideas of the convergence and interaction of historical forces.
Changes in trends or situations are the result of the clashes and interactions between various factors and forces. What is so strange about that? (Records of the Historian)
Changes in trends or situations are determined by heaven, not by the numbers of people. (The History of Zhou of the Northern Dynasties)