International integration is deepening, so people develop in all aspects. In society, communities with individuals have relationships in humans' material and spiritual life. When society grows, more people's knowledge of the world needs to learn so that people can understand themselves and act for the development of society. The article studies the thought of Thomas Aquinas to clarify human nature in social life. The paper uses analytical, synthesis, and argumentative methods to explain human nature with its behaviors and perceptions in social life; Aquinas argued that it is human nature to do the right thing to achieve happiness. However, society is more progressive and liberals, but people always realize their lives have many injustices and difficulties. People want their lives to be happy and good but feel depressed. In this article, in an excellent society, people live according to the law and adjust their behavior according to the regulations of society; each person in the society is also better, from which the society is also humane and reasonable that the basis for building a better society in Vietnam.