Populorum Progressio §63

⁶³ Racism is not the exclusive attribute of young nations, where sometimes it hides beneath the rivalries of clans and political parties, with heavy losses for justice and at the risk of civil war. During the colonial period it often flared up between the colonists and the indigenous population, and stood in the way of mutually profitable understanding, often giving rise to bitterness in the wake of genuine injustices. It is still an obstacle to collaboration among disadvantaged nations and a cause of division and hatred within countries whenever individuals and families see the inviolable rights of the human person held in scorn, as they themselves are unjustly subjected to a regime of discrimination because of their race or their color.