In this article, the analysis of two central concepts of the work of Hannah Arendt: the radical evil and the bana-lity of evil is realized. In development, the relationships between the conditions of the moral being and the poli-tical being are explored. The main thesis holds that the emergence of radical evil in the history of the twentieth century excludes the political action of human relations and that the political is born in the plurality of human relations, and its destruction has to do with unreflective attitude, To think and judge one’s own actions and those of other people; However, the political sphere can be protected if people reaffirm their difference if they are able to find themselves in the activity of thought, at least in certain moments of social crisis. Thought may not pro-tect men from evil, but it does maintain the condition of human plurality.