Encyclical

An encyclical was originally a circular letter sent to all the churches of a particular area in the ancient Roman Church. At that time, the word could be used for a letter sent out by any bishop. The word comes from Late Latin encyclios (from Latin encyclius, a Latinization of Greek ἐγκύκλιος enkyklios meaning "circular", "in a circle", or "all-round", also part of the origin of the word encyclopedia).

The term has been used by Catholics, Anglicans and the Eastern Orthodox.

Although the term "encyclical" originally simply meant a circulating letter, it acquired a more specific meaning within the context of the Catholic Church. In 1740, Pope Benedict XIV wrote a letter titled "Ubi Primum", which is generally regarded as the first encyclical in a modern sense. The term is now used almost exclusively for a kind of letter sent out by the Pope.

For the modern Roman Catholic Church, a Papal encyclical is specific category of papal document, a kind of letter concerning Catholic doctrine, sent by the Pope and usually addressed especially to patriarchs, primates, archbishops and bishops who are in communion with the Holy See. The form of the address can vary widely, and may concern bishops in a particular area, or designate a wider audience. Papal encyclicals usually take the form of a papal brief due to their more personal nature as opposed to the formal papal bull. They are usually written in Latin and, like all papal documents, the title of the encyclical is usually taken from its first few words (its incipit).

Within Catholicism in recent times, an encyclical is generally used for significant issues, and is second in importance only to the highest ranking document now issued by popes, an Apostolic Constitution. However, the designation "encyclical" does not always denote such a degree of significance. The archives at the Vatican website currently classify certain early encyclicals as Apostolic Exhortations, a term generally applied to a type of document with a broader audience than the bishops alone.

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