The Catholic Church first prohibited Catholics from membership in Masonic organizations and other secret societies in 1738. Since then, at least eleven popes have made pronouncements about the incompatibility of Catholic doctrines and Freemasonry. From 1738 until 1983, Catholics who publicly associated with, or publicly supported, Masonic organizations were censured with automatic excommunication. Since 1983, the prohibition on membership exists in a different form. Although there was some confusion about membership following the 1962-1965 Second Vatican Council (Vatican II), the Church continues to prohibit membership in Freemasonry because it believes that Masonic principles and rituals are irreconcilable with Catholic doctrines. The current norm, the 1983 Congregation for the Doctrine of the Faith's (CDF) Declaration on Masonic associations, states that "faithful who enroll in Masonic associations are in a state of grave sin and may not receive Holy Communion" and membership in Masonic associations is prohibited. The most recent document about the "incompatibility of Freemasonry with the Catholic faith" was issued in 1985.
History
In 1736, the Inquisition investigated a Masonic lodge in Florence, Italy, which it condemned in June 1737. The lodge had originally been founded in 1733 by the English Freemason Charles Sackville, 2nd Duke of Dorset, but accepted Italian members, such as the lodge's secretary Tommaso Crudeli. Also in 1736, on 26 December, Andrew Michael Ramsay delivered an oration to a masonic meeting in Paris on the eve of the election of Charles Radclyffe as Grand Master of the French Freemasons. In March 1737 he sent an edited copy to the chief minister, Cardinal André-Hercule de Fleury, seeking his approval for its delivery to an assembly of Freemasons, and his approval of the craft in general. Fleury's response was to brand the Freemasons as traitors, and ban their assemblies. This ban, and the Italian investigation led, in 1738, to Pope Clement XII promulgating In eminenti apostolatus, the first canonical prohibition of Masonic associations.
Clement XII wrote that the reasons for prohibiting masonic associations are that members, "content with form of natural virtue, are associated with one another" by oaths with "grave penalties" "to conceal in inviolable silence whatever they secretly do together." These associations have aroused suspicions that "to join these associations is precisely synonymous with incurring the taint of evil and infamy, for if they were not involved in evil doing, they would never be so very averse to the light [of publicity]." "The rumor [of these doings] has so grown that" several governments have suppressed them "as being opposed to the welfare of the kingdom." Clement XII wrote, that these kinds of associations are "not consistent with the provisions of either civil or canon law" since they harm both "the peace of the civil state" and "the spiritual salvation of souls."
Pope Leo XII attempted to assess the extent and influence of anti-social organizations. Leo XII inserted and confirmed the texts of , , and , in his 1825 constitution Quo graviora "to condemn them in such a way that it would be impossible to claim exemption from the condemnation."
Reiteration of ban on membership by subsequent popes
The ban in In eminenti apostolatus was reiterated and expanded upon by Benedict XIV (1751), Pius VII (1821), Leo XII (1825), Pius VIII (1829), Gregory XVI (1832), Pius IX (1846, 1849, 1864, 1865, 1869, 1873).
"The decisive impetus for the Catholic anti-Masonic movement" was Humanum genus, promulgated by Pope Leo XIII in 1884. Leo XIII wrote that his primary objection to Masonry was naturalism, his accusations were about pantheism, rationalism, and naturalism; but not about Satanism. Leo XIII analysed continental Grand Orient type philosophical "principles and practices." While naturalism was present everywhere in other types of lodges, "the subversive, revolutionary activity characteristic of the Grand Orient lodges of the continent" was not. Leo XIII "emphasises that 'the ultimate and principle aim' of Masonry 'was to destroy to its very foundations any civil or religious order established throughout Christendom, and bring about in its place a new order founded on laws drawn out of the entrails of naturalism'."