The aim of this paper is to show that school segregation not only has an impact on school achievement, but also on more qualitative issues such as the perception of inequalities and the feeling of discrimination. I propose an explanation for why the feeling of being trapped in segregated, 'disreputable' public schools, a feeling which is shared among people from disadvantaged and immigrant backgrounds, as well as parts of the lower-middle class, has a deep impact on social cohesion. We will see how this encourages working-class people to think more in terms of discrimination (segregation as the result of an intentional process) rather than in terms of inequality, calling into question public schools' capacity for guaranteeing equal opportunity. This is another way of analyzing how people facing an unequal context perceive injustice.