'Quanta Cura & The Syllabus of Errors' Summary

In the encyclical letter Quanta Cura, Pope Pius IX condemns a wide range of modern errors, including rationalism, liberalism, indifferentism, naturalism, pantheism, and communism. He also asserts the primacy of the pope over all other bishops and the infallibility of the pope when speaking ex cathedra on matters of faith and morals. The Syllabus of Errors, which is attached to the encyclical, lists eighty specific propositions that are condemned as heretical or erroneous. These propositions include the following: * The Roman Pontiff is not infallible when he defines, by his apostolic authority, that which is to be believed in matters of faith and morals. * The Church has not the power to define dogmatically that the religion of the Catholic Church is the only true religion. * It is lawful to deny the existence of God and to profess atheism. * Materialism and rationalism are not at all repugnant to the divine faith. * The Roman Pontiff can and ought to reconcile himself with progress, liberalism, and modern civilization.