How to Reference Encyclical Letters in a Bibliography

Encyclicals are formal letters or proclamations from the Catholic pope to the bishops and patriarchs, and by extension to all believers of the universal Church. Papal encyclicals are also a valuable resource for many scholars. Secular observers as well as practicing Catholics often turn to them for information on Catholic belief, or on the general tone of society during a certain era.

The Meaning of Encyclicals

The term "encyclical" comes from the Greek for a circular letter, so called because of the encyclical's wide dissemination (see References 5). In the Middle Ages, authoritative papal letters were often called "bulls", from the Latin "bulla," or seal, because of the ornate lead seal used to show the importance of the letter. Encyclicals written by the pope are often, but not always, considered to be infallible. That is, Catholics believe that the pope is guided by God and unerring when he teaches solemnly on matters of faith and morals (a pope would have no special authority when he talked about, for example, his favorite restaurant in Rome).

Encyclical Topics

The number of encyclicals issued by the Catholic popes have greatly increased over the last 200 years, with some popes authoring over 80 encyclicals. While some encyclicals deal with specific doctrinal issues and can be quite technical, others address broader social problems like nuclear proliferation, the excesses of laissez-faire capitalism, and the relationship between belief and science. In the nineteenth century, many popes adopted an antagonistic attitude towards modernity, and even put out encyclicals challenging ideas like liberalism and religious freedom. After the Second Vatican Council in the 1960s, however, many Catholic encyclicals adopted a more positive, hopeful tone, seeking to give consolation to modern people as they faced the challenges of life.

Online Encyclicals

The Vatican website is a good place to look for papal encyclicals, as they have full online copies of many important encyclicals from the nineteenth century up to today, categorized by the popes who issued them.

Conveniently, MLA no longer requires the use of URLs when citing websites, as web addresses may change and are not reliable ways to track back to the document. When citing an online papal encyclical, one will list the pope who authored it, the full title of the encyclical, the full title of the website, the copyright holder, and the date on which the document was accessed on the web. For example:

Pope Pius XI. "Mit Brennender Sorge- With Burning Sorrow, Encyclical Letter, Pius XI." Vatican: The Holy See. Vatican Website. Libreria Editrice Vaticana. 23 July 2013.

Print Encyclicals

One must also note when citing encyclicals that the pope is always listed by his papal title, like Pius XI, rather than his legal name before becoming pope, which for Pius XI was Achille Ratti. Works in which the pope writes without invoking his office are still attributed to his prior name. For example, Pope Benedict XVI authored several books under the name Joseph Ratzinger.

Encyclicals also typically have an official Latin title as well as their local translations, with the exception of Mit Brennender Sorge, which was titled in German. For print citations, one simply lists the pope's title, the full title of the encyclical and its status as an encyclical, the place of publication, publisher and date of publication, and that it is a print source.