The Roman Catholic Church has always been an attractive target for conspiracy theorists, due in large part to its elaborate and sometimes mysterious-seeming rituals, its associations with secret societies like the Knights Templar and the Rosicrucians, and even its sometimes defensive reaction to scandals like the revelations of recent years about child-molesting priests.

But what's most remarkable is that the church has also become a target for large number of Catholic conspiracy theorists -- and the tales these paranoid believers spin make The Da Vinci Code look like the work of a novice.

There are literally dozens of conspiracy theories that circulate, in particular, in the world of "radical traditionalist" Catholics. They range from the notion that the "perfidious" Jews are engaged in a global plot against the church and Christianity to the idea that Pope Paul VI (1963-78) was secretly poisoned, imprisoned by renegade Vatican officials, and replaced with a surgically altered, professional actor.

What follows are descriptions of the two most popular conspiracy theories embraced by radical traditionalists. Both attempt to explain how Vatican II (1962-65), the liberalizing church council that offered an olive branch to Jews and is the traditionalists' chief bogeyman, could ever have come to pass.

The Judeo-Masonic Conspiracy
By far the most popular conspiracy theory in the radical traditionalist pantheon is the idea that Jewish Masons, or alternatively Masons under Jewish control, have been working secretly for some 300 years to take over and deform the Catholic church -- the so-called Judeo-Masonic conspiracy.

The best-known iteration of this theory appears in a book by Catholic Family News (see also group profile, p. 29) editor John Vennari, The Permanent Instruction of the Alta Vendita: A Masonic Blueprint for the Subversion of the Catholic Church. The book claims to present, along with Vennari's commentary, supposedly secret Masonic papers (the "Alta

Vendita") that detail plans to subvert the church by creating priests secretly favoring "modern thought rooted in the French Revolution's 'Declaration of the Rights of Man'."

Vennari argues that Jews push the rationalistic beliefs of the Masons, who supported notions of human equality and social progress, as a tool to serve Jewish interests. Vennari keys in on the idea that when Jews were finally given nominal equal rights early on in France's Third Republic (1870-1940), the separation of church and state became a reality -- anathema to Vennari.

Catholic fears about Masonic power have not been limited to Vennari. Pope Leo XIII (1878-1903), for one, branded Freemasonry an enemy of "religion and society" and wrote in an 1884 encyclical that Masons sought to impose a Kingdom of Satan on earth. The notorious French Catholic anti-Semite, Eduard Drumont, called for excluding Jews from society in his La Libre Parole newspaper and took part in an international anti-Masonic congress held in Italy in 1894.

Enthusiasts of the Judeo-Masonic conspiracy theory see their enemies as largely successful. They typically believe that the plotters have actually held the papacy ever since 1958 and were the engineers of the Vatican II reforms.

The Cardinal Siri Thesis
A second conspiracy theory, often referred to as the "Cardinal Siri thesis," essentially builds on the alleged Judeo-Masonic plot. But it adds a "sedevacantist" twist -- the idea that the papacy has been filled by false popes for decades.

According to this theory, Giuseppe Siri, an archconservative cardinal from Genoa, was elected pope at the 1958 conclave of cardinals, and this election was signaled in the traditional manner, with billows of white smoke pouring from a Vatican chimney. Vatican officials at the time said there had been a mistake in the fire pit, but Siri supporters claim that he was actually unseated through the nefarious machinations of liberal cardinals, who replaced Siri with Cardinal Angelo Roncalli. Roncalli became the first "false" pope, known to the world as John XXIII.

In 1963, when the papacy fell empty once more, Siri was again bested by evil forces within the church, Siri conspiracy theorists allege. Although Siri won election, they claim, he was replaced by Cardinal Giovanni Battista Montini, who became the second "false" pope, Paul VI. Some Siri partisans blame not only liberal cardinals but also unspecified outside forces that threatened the Vatican with nuclear annihilation if Siri were actually seated as pope.

Siri conspiracy theorists say that the cardinal was then exiled to a Roman monastery and ordered to remain silent. As proof, they cite a 1985 interview Siri gave in which he said, "I am bound by the secret. … I can say nothing." Some also claim that he told a Vietnamese priest in 1988, the year before he died, that he was the true pope. And many blame Siri's plight on B'nai B'rith, an international Jewish humanitarian organization, saying it is part of the Judeo-Masonic plot.

Ultimately, Siri partisans argue, there has been no true pope in power in Rome since 1958. One major problem for the conspiracy theorists: Cardinal Siri remained in full communion with the church throughout his life, celebrating the post-Vatican II Mass and defending the church reforms the council brought.