Immortale Dei - Pope Leo XIII
Refuting the charges that the Catholic Church would be against the interests of civil society, Pope Leo XIII, in the Encyclical Immortale Dei, of 1885, exposes the doctrine of the Church about the constitution of the States.
Syllabus - Pope Pio IXThis most up-to-date document consists on a list of thesis condemned by Pope Pius IX. It condemns many errors broadly adopted in our times, such as pantheism, religious indifferentism (ecumenism), socialism, communism, laicism, etc.
Pascendi Dominici Gregis - S. Pio XModernism is a heresy which has deeply penetrated into all segments of society, including – and mainly – ‘the very veins and heart of the Church’. The modernism was the last heresy condemned by the Church and the only condemnation in the whole XXth century. In spite of that, its errors are found in the mentality of many clergymen of nowadays. In this encyclical, S. Pius X makes a masterly exposition of the modernist system, which can be defined as ‘the synthesis of all heresies’. It condemns, among others, agnosticism, religious immanence and its religious sentiment, evolution of the dogmas, etc.
Quanta Cura - Pope Pio IXEncyclical condemning errors of communism, socialism and protestantism, promulgated by Pope Pius IX.
Mortalium Animos - Pope Pius XIEncyclical of mandatory reading which scourges the errors - very praised nowadays - of ecumenism, stating once again that the Catholic Religion is the only true.
Mirari Vos - Pope Gregório XVIEncyclical of Pope Gregory XVI which deals with the immutability of Church's doctrine and discipline, with highlight to the doctrine on cleric celibacy, so attacked in our days. It condemns freedom of consciousness and of the press, among others.