In the Boston Globe‘s Conspiracies So Vast Darrin M. McMahon discusses the origins of modern conspiracy theory:
Conspiracies have been around for as long as there have been people to plot. Yet the courtly coups and palace intrigues that animate the pages of Machiavelli’s ‘The Prince’ were very different from the more generalized theories of conspiracy that first began to circulate, ironically, in that crucible of modernity known as the Age of Reason. The 18th-century Enlightenment saw the emergence of vague, shadowy rumors of international machinations, lurid accounts of the collusion of Freemasons, Jesuits, or radical philosophers, ghastly tales of plots hatched in cells throughout the world to infiltrate governments, topple kings, eradicate religion, and corrupt morals and beliefs.Whereas the older plots were usually localized (and often genuine), reflecting a face-to-face world in which public life was controlled by the actions of powerful individuals, the newer variants tended to be open-ended and elusive in their aims. Titillating, consoling, and disturbing all at once, these were accounts well-suited to the newly expanding print culture of the 18th century, which brought together formerly isolated groups into virtual communities of opinion now sharing the same newspapers, novels, placards, and pamphlets. The new conspiracies also traveled well by word of mouth — thriving among the 18th century’s rapidly growing populations, in which distrust was fueled by the anonymity of urban environments and insecurity heightened by mobility, dislocation, and bewildering socioeconomic change.
In many cases these new tales were entirely fictitious, like the rumors that consumed Paris in the 1750s that servants of the crown were snatching vagrant children to provide baths of blood for King Louis XV. In other instances they were more immediately plausible, as with the widespread conspiracy rhetoric among American colonists, who drew on decades of distrust of Georgian kings and colonial agents.
In still other cases, conspiracy theories metastasized from an original germ of truth. Fears of the Illuminati, for example, still invoked to this day, were originally fed by the discovery in the 1780s of an actual conspiracy led by a Bavarian professor at the University of Ingolstadt, Adam Weishaupt. His brotherhood of “enlightened ones,” the Society of the Illuminati, aimed to infiltrate established Masonic lodges throughout Europe with the goal of disseminating republican and anticlerical beliefs. The conspiracy was discovered long before it could have any real effect. But this did nothing to stem the alarm that spread in its wake.
Fanned by the terrible upheavals of the French Revolution, tales of the Illuminati flourished, taking their place alongside the dastardly accounts of “Monied Interests,” Masons, Jacobins, Rosicrucians, Jesuits, and Jews. When the President of Yale, Timothy Dwight, preached a sermon before alarmed undergraduates in 1797, warning of the machinations of the Illuminati conspiracy in the New World, he was merely adding an early Yankee voice to what would soon become a full-blown national panic. The American Bavarian Illuminati scare of 1798-1800 swept up the likes of Alexander Hamilton, and brought the country to the brink of civil war.
Dwight and Hamilton were in good company. From Voltaire and Rousseau to David Hume and Edmund Burke, some of the century’s finest minds were ready to countenance conspiracies of one form or another. That fact makes it difficult to dismiss the Enlightenment’s fascination with these dark developments as simply irrational aberrations. On the contrary, as the Pulitzer Prize-winning historian Gordon S. Wood has argued, Enlightenment conspiracy theories may have represented a transitional step on the way to a more nuanced and “scientific” understanding of the world.
For an age in the process of demystifying Nature, to attribute cause and effect to magic or Fate, the Devil or the hidden hand of Providence was no longer sufficient. Searching for rational patterns to explain the laws of humanity as they explained the laws of the natural world, Enlightenment observers ran up against the complexity and contingency of human affairs.
Large-scale phenomena like the transition to capitalism, or the American or French Revolutions, did not readily lend themselves to simple patterns. Conspiracy was a way to ascribe order to the seemingly chaotic, make an irrational world appear rational without ascribing agency to nonhuman forces. Conspiracy, in short, was comforting, even if that comfort could have dark consequences.