The paper analyzes different theoretical standpoints related to the concepts of "open society" and "closed society", with a special focus on Popper. Through an in-depth analysis of the most important works of the Austrian philosopher, it is possible to understand the relationship between the fallibility of human knowledge and the openness of the society. Our awareness of the epistemic limits of human thinking can lead to the formation and promotion of open and democratic societies. Particular attention is to be paid toward those philosophical systems that can, even unintentionally, promote an authoritarian society by assuming the political and historical development as necessary.
Keywords: Open society; closed society; knowledge; democracy.