The idea of a widespread Freemason conspiracy originated in the late 1700's and flourished in the US in the 1800's. Persons who embrace this theory often point to purported Masonic symbols such as the pyramid and the eye on the back of the dollar bill as evidence of the conspiracy. Allegations of a freemason conspiracy trace back to British author John Robison who wrote the 1798 book Proofs of a Conspiracy Against All the Religions and Governments of Europe, carried on in the secret meetings of Free Masons, Illuminati, and Reading Societies, collected from good authorities. Robison influenced French author Abbé Augustin Barruel, whose first two volumes of his eventual four volume study, Memoirs Illustrating the History of Jacobinism, beat Robison's book to the printer. Both Robison and Barruel discuss the attempt by Bavarian intellectual Adam Weishaupt to spread the ideas of the Enlightenment through his secretive society, the Order of the Illuminati.
Weishaupt was appointed a professor at the University of Ingolstadt in Germany around 1772 and elevated to the post of professor of Canon Law in 1773 or 1775 (sources conflict), the first secularist to hold that position previously held by clergy. Weishaupt began planning a group to challenge authoritarian Catholic actions in 1775, the group (under a different name) was announced on May 1, 1776. This group evolved into the Illuminati. The Enlightenment rationalist ideas of the Illuminati were, in fact, brought into Masonic lodges where they played a role in a factional fight against occultist philosophy. The Illuminati was suppressed in a series of edicts between 1784 and 1787, and Weishaupt himself was banished in 1785.
Weishaupt, his Illuminati society, the Freemasons, and other secret societies are portrayed by Robison and Barruel as bent on despotic world domination through a secret conspiracy using front groups to spread their influence.
Barruel claimed the conspirators "had sworn hatred to the altar and the throne, had sworn to crush the God of the Christians, and utterly to extirpate the Kings of the Earth." For Barruel the grand plot hinges on how Illuminati "adepts of revolutionary Equality and Liberty had buried themselves in the Lodges of Masonry" where they caused the French revolution, and then ordered "all the adepts in their public prints to cry up the revolution and its principles." Soon, every nation had its "apostle of Equality, Liberty, and Sovereignty of the People."
The major immediate political effect of allegations of an Illuminati Freemason conspiracy in Europe was to mobilize support for national oligarchies traditionally supported by the Catholic Church hierarchy. Across Europe authoritarian governing elites were coming under attack by reformist and revolutionary movements demanding increased political rights under secular laws. The ideas of the Enlightenment were incorporated by the leaders of both the French and American revolutions, and in a sense, these Enlightenment notions were indeed subversive to the established social order, although they were hardly a secret conspiracy. The special status of the Catholic Church in European nation-states was actually threatened by the ideas being discussed by the Illuminati and the rationalist wing of the Freemasons.
Several common conspiracist themes emerge from these two books. The Enlightenment themes of equality and liberty are designed to destroy respect for property and the natural social hierarchy. Orthodox Christianity is to be destroyed and replaced with universalism, deism...or worse. Persons with a cosmopolitan outlook--encouraging free-thinking and international cooperation--are to be suspect as disloyal subversive traitors out to undermine national sovereignty and promote anarchy.
Shortly after the Barruel book was published, conspiracy theories about the Illuminati Freemasons were mixed with antisemitism in Europe. This confluence took place much later in the US.
Signs of the Freemasons :-