Breaking a 18th C cipher reveals hidden history of Freemasonry and freethought

Noah Shachtman's long Wired feature "They Cracked This 250-Year-Old Code, and Found a Secret Society Inside," tells the intriguing story of the cracking of the "Copiale" cipher, a strange text left behind by a mid-18th-century secret society called the Oculists. The Oculists had formerly been remembered as being concerned with performing and perfecting eye surgeries, but the Copiale cipher revealed them to have been either spies within Freemasonry, or Freemasons who'd formed another secret society to record and safeguard Mason rituals in the face of persecution from the Catholic church. I was particularly intrigued by the parallels Shachtman draws between members of secret societies and contemporary online secret groups, both using cryptography to guard their freethought from intolerant state snooping.

Hundreds of thousands of Europeans belonged to secret societies in the 18th century, Önnerfors explained to Megyesi; in Sweden alone, there were more than a hundred orders. Though they were clandestine, they were often remarkably inclusive. Many welcomed noblemen and merchants alike—a rare egalitarian practice in an era of strict social hierarchies. That made the orders dangerous to the state. They also frequently didn’t care about their adherents’ Christian denomination, making these orders—especially the biggest of them, Freemasonry—an implicit threat to the authority of the Catholic Church. In 1738 Pope Clement XII forbade all Catholics from joining a Masonic lodge. Others implied that the male-only groups might be hotbeds of sodomy. Not long after, rumors started that members of these orders actually worshipped the devil.
These societies were the incubators of democracy, modern science, and ecumenical religion. They elected their own leaders and drew up constitutions to govern their operations. It wasn’t an accident that Voltaire, George Washington, and Ben Franklin were all active members. And just like today’s networked radicals, much of their power was wrapped up in their ability to stay anonymous and keep their communications secret.
After reading the Oculists’ cipher, Önnerfors suggested that it described one of the more extreme groups. Forget the implicit threats to the state or church. In part of the Copiale, there’s explicit talk about slaying the tyrannical “three-headed monster” who “deprive[s] man of his natural freedom.” There’s even a call for a “general revolt.” Remember, Önnerfors told the code-breakers, this book was written in the 1740s—30 years before the Declaration of Independence. “To someone at the time,” he added, “this would be like reading a manifesto from a terrorist organization.”

They Cracked This 250-Year-Old Code, and Found a Secret Society Inside