The purpose of this research is to investigate how high school teachers from a public school in the city of Rio de Janeiro perceive and react when they are faced with prejudice or discriminatory behavior among students. This research also intended to grasp which conceptions of morality serve as a basis for the teachers actions, either implicitly or explicitly. By using the connection between regulative conceptions of justice and happiness that are present in Kant and Aristotle s work, and considering that these concepts are usually seen in an excluding way, this research suggests the possibility of these concepts complementing each other ,as well as being mutually connected. As for the methodological choices, the research involved on extensive literature review along with fieldwork and semi- structured interviews with 17 teachers, who volunteered. One result of the research that is important to highlight is that the types of prejudice and discrimination that were most perceived by the teachers were related to sexual orientation, racial and ethnic diversity. On the other hand, the least noted were related to religion, cognitive difference, physical appearance and place of origin. Referring to the actions taken by these teachers while facing this discriminatory behavior, the majority mentioned that they would firmly oppose them, however the fieldwork showed that some teachers don t notice this behavior, or seem to ignore the suffering some students are exposed to. Maybe due to the limits of the chosen method, the research couldn t explicit the articulation between the concepts for justice and happiness, as well as their conceptions of morality. However, it was observed that when the teachers were faced with situations in which an urgent decision was required, they prioritized justice at the expense of happiness. Finally, the research pointed out that there are still limits in teaching education, training and formation with regard to the prejudice and discrimination that take place at school.