Catholic social teaching is a body of doctrine developed by the Catholic Church on matters of poverty and wealth, economics, social organization and the role of the state. Its foundations are widely considered to have been laid by Pope Leo XIII‘s 1891 encyclical letter Rerum Novarum, which advocated economic Distributism and condemned Socialism, although its roots can be traced to the writings of Catholic thinkers such as St. Thomas Aquinas and St. Augustine of Hippo, and is also derived from concepts present in the Bible.
According to Pope Benedict XVI, its purpose “is simply to help purify reason and to contribute, here and now, to the acknowledgment and attainment of what is just…. [The Church] has to play her part through rational argument and she has to reawaken the spiritual energy without which justice…cannot prevail and prosper”, According to Pope John Paul II, its foundation “rests on the threefold cornerstones of human dignity, solidarity and subsidiarity”. These concerns echo elements of Jewish law and the prophetic books of the Old Testament, and recall the teachings of Jesus Christ recorded in the New Testament, such as his declaration that “whatever you have done for one of these least brothers of Mine, you have done for Me.”
Catholic social teaching is distinctive in its consistent critiques of modern social and political ideologies both of the left and of the right: liberalism, communism, feminism, atheism, socialism, libertarianism, capitalism, fascism, and Nazism have all been condemned, at least in their pure forms, by several popes since the late nineteenth century.