Papal ban of Freemasonry

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 1965 Second Vatican Council (Vatican II), the Church continues to prohibit membership in Freemasonry because it concluded 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 CDF document about the "incompatibility of Freemasonry with the Catholic faith" was issued in 1985.

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.

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