Pope Leo XIII in Rerum:
"The great mistake made in regard to the matter now under consideration is to take up with the notion that class is naturally hostile to class, and that the wealthy and the working men are intended by nature to live in mutual conflict.... Each needs the other: capital cannot do without labor, nor labor without capital."
Pope Leo XIII issued this encyclical on the"new things" in the modern world, condemning both socialism and laissez-faire capitalism. He defended private property and upheld the right to just wages and labor organization. In the United States, the impetus of the encyclical as well as national social and economic developments focused the Church's attention more closely on social issues and laid the foundation for a long and extensive cooperation between Catholics and organized labor.