These reforms and writings of Pius XII were intended to establish Eastern Orientals as equal parts of the mystical body of Christ, as explained in the encyclical Mystici Corporis.

This view was defended in the 20th century by Gabriel Roschini, and more generally, by Pope Pius XII in his encyclical Mystici Corporis as official doctrine of the Catholic Church.

The papal encyclical Mystici Corporis expresses the dogmatic ecclesiology of the Catholic Church thus: " if we would define and describe this true Church of Jesus Christ – which is the One, Holy, Catholic, Apostolic, Roman Church – we shall find no expression more noble, more sublime, or more divine, than the phrase which calls it ‘ the Mystical Body of Jesus Christ.

The concept of the Second Eve has continued to remain part of Catholic teachings, e. g. Pope Pius XII referred to it in the encyclical Mystici Corporis Christi and Pope John Paul II referred to it in a General Audience at the Vatican in 1980.

This term was used as the first words, and so as the title, of the encyclical Mystici Corporis Christi of Pope Pius XII.

Ecclesiology at the time was centered on the text Mystici Corporis Christi ( often simply called Mystici Corporis ), the encyclical promulgated by Pope Pius XII on 29 June 1943, and Tromp was widely thought to have participated in the authoring of the text with the Pope.

Mystici Corporis Christi ( June 29, 1943 ) is a papal encyclical issued by Pope Pius XII during World War II, on the Church as the Mystical Body of Christ.

Pope Paul VI quoted Mystici Corporis from Pius XII verbatim in his first encyclical Ecclesiam Suam: “ Consider, then, this splendid utterance of Our predecessor: ' The doctrine of the Mystical Body of Christ, which is the Church, a doctrine revealed originally from the lips of the Redeemer Himself.

* 1884 – Pope Leo XIII publishes the encyclical Humanum Genus.

In recent times, its teaching has been most notably expressed in the Vatican II council documents Unitatis Redintegratio ( 1964 ), Lumen Gentium ( 1964 ), Nostra aetate ( 1965 ), an encyclical issued by Pope John Paul II: Ut Unum Sint ( 1995 ), and in a document issued by the Congregation for the Doctrine of the Faith, Dominus Iesus in 2000.

Distributism ( also known as distributionism or distributivism ) is an economic philosophy that developed in England in the early 20th century based upon the principles of Catholic social teaching, especially the teachings of Pope Leo XIII in his encyclical Rerum Novarum and Pope Pius XI in Quadragesimo Anno.

* Rerum Novarum ( 1891 ) papal encyclical by Pope Leo XIII

* Quadragesimo Anno ( 1931 ) papal encyclical by Pope Pius XI

* Centesimus Annus ( 1991 ) papal encyclical by Pope John Paul II

" The attempt by some twentieth-century Catholic theologians to present the Eucharistic change as an alteration of significance ( transignification rather than transubstantiation ) was rejected by Pope Paul VI in his 1965 encyclical letter Mysterium fidei In his 1968 Credo of the People of God, he reiterated that any theological explanation of the doctrine must hold to the twofold claim that, after the consecration, 1 ) Christ's body and blood are really present ; and 2 ) bread and wine are really absent ; and this presence and absence is real and not merely something in the mind of the believer.

* Ecclesiam Suam, an encyclical of Pope Paul VI on the Catholic Church given at St. Peter's, Rome, on the Feast of the Transfiguration, August 6, 1964, the second year of his Pontificate

The Catholic Church also has taught that faith and reason can and must work together, in the Papal encyclical letter issued by Pope John Paul II, Fides et Ratio (" Faith and Reason ").

* 1906 – Pope Pius X publishes the encyclical Vehementer nos.

Humanae Vitae ( Latin Of Human Life ) is an encyclical written by Pope Paul VI and issued on 25 July 1968.

There were two Papal committees and numerous independent experts looking into the latest advancement of science and medicine on the question of artificial birth control, which were noted by the Pope in his encyclical.

In a partial reaction, Pope Pius XI wrote the encyclical Casti connubii ( On Christian Marriage ) in 1930, reaffirming the Catholic Church's belief in various traditional Christian teachings on marriage and sexuality, including the prohibition of artificial birth control even within marriage.

In Latin America, much support developed for the Pope and his encyclical.

There is also a particular view in ecclesiastical history and in the history of dogmas which has been described as historicist by Pope Pius XII in the encyclical Humani Generis.

* Pope St. Pius X's encyclical Pascendi, in which he defines Modernism as " the synthesis of all heresies ".

* 1891 – Pope Leo XIII defends workers ' rights and property rights in the encyclical Rerum Novarum, the beginning of modern Catholic social teaching.

* 1939 – Pope Pius XII publishes his first major encyclical entitled Summi Pontificatus.

The Second Vatican Council referred to all bishops as " vicars and ambassadors of Christ ", and this description of the bishops was repeated by Pope John Paul II in his encyclical Ut unum sint, 95.

Noting improvements in archaeology, the encyclical reversed Pope Leo XIII's encyclical, which had only advocated going back to the original texts to resolve ambiguity in the Latin Vulgate.

* Quanta Cura, a Papal encyclical issued by Pope Pius IX on 8 December 1864

In the English-speaking world, the Douay-Rheims Bible — translated from the Latin Vulgate by expatriate recusants in Rheims, France in 1582 ( New Testament ) and in Douai, France in 1609 ( Old Testament )— which was revised by Bishop Richard Challoner in 1749 – 1752 ( the 1750 revision is that which is printed today ), was, until the prompting for " new translations from the original languages " given by Pope Pius XII in the 1942 encyclical letter Divino afflante spiritu and the Second Vatican Council, the translation used by most Catholics ( after Divino afflante spiritu, translations multiplied in the Catholic world, just as they multiplied in the Protestant world around the same time beginning with the Revised Standard Version, with various other translations being used around the world for English-language liturgies, ranging from the New American Bible, the Jerusalem Bible, the Revised Standard Version Second Catholic Edition, and the upcoming English Standard Version Catholic lectionary ).

However, this doctrine was rejected by Pope Paul VI in his encyclical Mysterium Fidei.

Most notably, early in 1937, Pacelli asked several German cardinals, including Cardinal Michael von Faulhaber to help him write a protest of Nazi violations of the Reichskonkordat ; this was to become Pius XI's 1937 encyclical, Mit brennender Sorge.

In his encyclical Mediator Dei, Pius XII links liturgy with the last will of Jesus Christ.

" In a review of Goldhagen's book, Mark Riebling counters that Pius used the word " Jew " in his first encyclical, Summi Pontificatus, published on 20 October 1939.

The hidden encyclical of Pius XI.

This affirmed the importance of Sacred Scripture as attested by Providentissimus Deus by Pope Leo XIII and the writings of the Saints, Doctors, and Popes throughout Church history but also approved historically conditioned interpretation of Scripture as presented in Pius XII's 1943 encyclical Divino Afflante Spiritu.

* February 11 – Pope Pius X publishes the encyclical Vehementer Nos.

* December 31 – The Papal encyclical Casti Connubii issued by Pope Pius XI stresses the sanctity of marriage, prohibits Roman Catholics from using any form of artificial birth control, and reaffirms the Catholic prohibition on abortion.

However, in 1937, Pope Pius XI issued an encyclical written in German, Mit brennender Sorge ( With Burning Anxiety ), in which he criticized Nazism, listed breaches of the Concordat signed between Germany and the Church in 1933, and condemned antisemitism.

Rosary as a family prayer was supported by Pope Pius XII in his encyclical Ingruentium Malorum: " The custom of the family praying of the Holy Rosary is a most efficacious means.

* Ingruentium Malorum, encyclical by Pope Pius XII ( on reciting the rosary )

* Pope Pius XII Rosary encyclical Ingruentium Malorum on the Vatican website

* The encyclical Quadragesimo Anno ( On Reconstruction of the Social Order, literally " in the fortieth year ") of 1931 by Pope Pius XI, encourages a living wage, subsidiarity, and advocates that social justice is a personal virtue as well as an attribute of the social order, saying that society can be just only if individuals and institutions are just.

In his encyclical Miserentissimus Redemptor on reparations, Pope Pius XI called Acts of Reparation to Jesus Christ a duty for Catholics and referred to them as " some sort of compensation to be rendered for the injury " with respect to the sufferings of Jesus.

Pius was particularly devoted to Mary ; his encyclical Ad Diem Illum expresses his desire through Mary to renew all things in Christ, which he had defined as his motto in his first encyclical.