A trend of extreme division could be seen in the research of social science and natural science, which has caused different degrees of negative impact on numerous subordinate disciplines of social science, and thus, resulting in no substantial breakthroughs in the research process of their basic theories. The purpose of this research is to explore the relationship between the state and society through the epistemological development of ontology, in order to solve a series of problems brought about by the relatively chaotic disciplinary theoretical system of international relations, area studies, and social science theories on the development of grounded theories, so as to break through the status quo of no paradigm. Therefore, in this paper, the author proposes to use natural science theories to perceive the social sciences and to analyse the evolution of the international system through natural science theories. Overall, this study puts international relations in a systemic perspective to carry out comprehensive and well-rounded research, and analyses the patterns and rules that exist in the international system. At the same time, the article also reveals the law of entropy change of the international system and analyses some decisive key elements within the system.