Arcanum is a Catholic

Catholic

The word catholic comes from the Greek phrase , meaning "on the whole," "according to the whole" or "in general", and is a combination of the Greek words meaning "about" and meaning "whole"...

 encyclical

Encyclical

An encyclical was originally a circular letter sent to all the churches of a particular area in the ancient Catholic Church. At that time, the word could be used for a letter sent out by any bishop...

 written in 1880 by Pope Leo XIII

Pope Leo XIII

Pope Leo XIII , born Vincenzo Gioacchino Raffaele Luigi Pecci to an Italian comital family, was the 256th Pope of the Roman Catholic Church, reigning from 1878 to 1903...

 on the topic of Christian

Christianity

Christianity is a monotheistic religion based on the life and teachings of Jesus as presented in canonical gospels and other New Testament writings...

 marriage. It was considered the forerunner to Pope Pius XI

Pope Pius XI

Pope Pius XI , born Ambrogio Damiano Achille Ratti, was Pope from 6 February 1922, and sovereign of Vatican City from its creation as an independent state on 11 February 1929 until his death on 10 February 1939...

's 1930 Casti Connubii

Casti Connubii

Castī Connūbiī was a papal encyclical promulgated by Pope Pius XI on December 31, 1930 in response to the Lambeth Conference of the Anglican church. It stressed the sanctity of marriage, prohibited Catholics from using any form of artificial birth control, and reaffirmed the prohibition on abortion...

 and Pope Paul VI

Pope Paul VI

Paul VI , born Giovanni Battista Enrico Antonio Maria Montini , reigned as Pope of the Catholic Church from 21 June 1963 until his death on 6 August 1978. Succeeding Pope John XXIII, who had convened the Second Vatican Council, he decided to continue it...

's 1968 Humanae Vitae

Humanae Vitae

Humanae Vitae is an encyclical written by Pope Paul VI and issued on 25 July 1968. Subtitled On the Regulation of Birth, it re-affirms the traditional teaching of the Catholic Church regarding married love, responsible parenthood, and the continuing proscription of most forms of birth...

.

Summary

Arcanum outlines the role of marriage in modern time, and goes through those actions which weaken the marriage contract such as polygamy

Polygamy

Polygamy is a marriage which includes more than two partners...

 and divorce

Divorce

Divorce is the final termination of a marital union, canceling the legal duties and responsibilities of marriage and dissolving the bonds of matrimony between the parties...

. The encyclical also posits the Church as a protector of marriage, and not one interfering in the marital relationship.

Further reading

• Full text of the Arcanum Letter, New Advent.org, 2007.