''The'' ''Catholic Encyclopedia: An International Work of Reference on the Constitution, Doctrine, Discipline, and History of the Catholic Church'', also referred to as the ''Old Catholic Encyclopedia'' and the ''Original Catholic Encyclopedia'', is an English-language
encyclopedia
An encyclopedia is a reference work or compendium providing summaries of knowledge, either general or special, in a particular field or discipline. Encyclopedias are divided into article (publishing), articles or entries that are arranged Alp ...
about Catholicism published in the United States. It was designed "to give its readers full and authoritative information on the entire cycle of Catholic interests, action and doctrine".
The first volume of the ''Catholic Encyclopedia'' appeared in March 1907 and the last three volumes appeared in 1912, followed by a master index volume in 1914 and later supplementary volumes. Its successor, the ''
New Catholic Encyclopedia
The ''New Catholic Encyclopedia'' (NCE) is a multi-volume reference work on Catholic Church, Roman Catholic history and belief edited by the faculty of the Catholic University of America in Washington, D.C. The NCE was originally published in 196 ...
'', was first published by the Catholic University of America in 1967.
''The'' ''Catholic Encyclopedia'' was published by the Robert Appleton Company (RAC) in New York City. RAC was a
publishing
Publishing is the activities of making information, literature, music, software, and other content, physical or digital, available to the public for sale or free of charge. Traditionally, the term publishing refers to the creation and distribu ...
company incorporated in February 1905 for the express purpose of publishing the encyclopedia. The five members of the encyclopedia's editorial board also served as the RAC directors. In 1912, the company changed its name was changed to The Encyclopedia Press. Publication of the encyclopedia's volumes was the sole business conducted by Encyclopedia Press during the project's lifetime.
Purpose

The ''Catholic Encyclopedia'' was designed to serve Catholics and other readers who wanted information about the church from the Catholic point of view. The encyclopedia records the accomplishments of Catholics and others in nearly all intellectual and professional pursuits, including the arts, education and science. While more limited in focus than other general encyclopedias, it was far broader in scope than previous efforts at comprehensive Catholic encyclopedias, which covered only internal Church affairs.
The ''Catholic Encyclopedia'' offers in-depth portrayals of historical and philosophical ideas, persons and events, from a Catholic perspective, including issues that divide Catholicism from
Protestantism
Protestantism is a branch of Christianity that emphasizes Justification (theology), justification of sinners Sola fide, through faith alone, the teaching that Salvation in Christianity, salvation comes by unmerited Grace in Christianity, divin ...
and other faith communities. Since the encyclopedia was first published starting in 1907 and has never been updated (versus the ''
New Catholic Encyclopedia
The ''New Catholic Encyclopedia'' (NCE) is a multi-volume reference work on Catholic Church, Roman Catholic history and belief edited by the faculty of the Catholic University of America in Washington, D.C. The NCE was originally published in 196 ...
''), many of its entries may be out of date either with respect to the wider culture or to the Catholic