Can the ancestry of freemasonry really be traced back to the Knights Templar? Is the image of the eye in a triangle on the back of the dollar bill one of its cryptic signs? Is there a conspiracy that stretches through centuries and generations to elevate this shadow organization with secret rituals and ties to world governments and religions? Myths persist and abound about the freemasons, Margaret C. Jacob notes. But what is their origin? How has an early modern organization of bricklayers and stonemasons aroused so much public interest? In The Origins of Freemasonry, Jacob throws back the veil from a secret society that turns out not to have been very secret at all.

As early as the 1650s, Jacob writes, records show how impoverished English and Scottish guilds of stonemasons began to admit relatives of members as well as prominent figures with philosophical interests. By 1750, membership was estimated in the tens of thousands, with perhaps a thousand women among them, and by the time of the French Revolution, well over 100,000 individuals in Europe and America had taken the Masonic Oath to the Grand Architect of the Universe.

What factors contributed to the extraordinarily rapid spread of freemasonry over the course of the eighteenth century, and why were so many of the era's most influential figures drawn to it? Using material from the archives of leading masonic libraries in Europe, Jacob examines masonic almanacs and pocket diaries to get closer to what living as a freemason might have meant on a daily basis. She explores the persistent connections between masons and nascent democratic movements, as each lodge set up a polity—often more honored in the breach than in the execution—where an individual's standing would be based on merit, rather than on birth or wealth, and she demonstrates, beyond any doubt, how active a role women played in the masonic movement. Membership implied an interest in government, as the lodges often functioned as schools where brothers and sisters learned to vote, to orate, to practice social discipline, and, not least, regularly to pay "taxes" to their lodge.

The Origins of Freemasonry separates fact from fiction, revealing the truth about an organization that fascinated the eighteenth-century public in much the same way it fascinates us today.

Margaret C. Jacob is Distinguished Professor of History at the University of California, Los Angeles. She is the author of many books, including The Enlightenment: A Brief History with Selected Texts and Scientific Culture and the Making of the Industrial West.