Entropy of the system is controlled by two fundamental laws: one is the second law of thermodynamics that is effective in closed systems, and the other is the principle of Maximum Entropy Production (MEP) that works in open systems. Although the former has been well-known as the law of increasing entropy for a long time, the latter was invented as a result of recent researches for non-equilibrium thermodynamics, which is not yet familiar with social scientists. It is crucial to study both of them in order to comprehend the behavior of entropy entirely, because it is not the second law of thermodynamics but the principle of MEP that reflects the creativity of entropy. In this paper, we focus on the role of the MEP principle, and try to extend it to social sciences. To be concrete, the diversity of societies that have emerged on the Earth is investigated from the viewpoint of MEP, after the original meaning of the MEP principle is explained using a simple human society model. We expect that the present paper contributes toward deepening the understanding of entropy in open systems that exist in the state far from equilibrium, and that the idea of MEP, the essence of non-equilibrium thermodynamics, is injected into the researches for various social phenomena. [ABSTRACT FROM AUTHOR]