Biagio doesn’t become a Freemason until after the first Napoleonic campaign, so he’s not sure when Cosimo becomes involved with the Masons. One day, two Spaniards arrive, seek out a local Freemason, and attend a meeting. The next day, Cosimo sneakily follows them from the trees to a tavern, where the men meet a man in a big black hat. The man in the hat begins to write a list. Cosimo announces himself and the two Spaniards acknowledge him, but the man in the hat looks down. Cosimo suggests that only spies refuse to show their faces; the man in the hat suggests that members of secret societies may also want to keep their identities secret. Cosimo spews confusing logic about which of them might be a member of a secret society, which causes the man in the hat to raise his head. It’s Father Sulpicio.
The fact that Biagio did eventually become a Freemason suggests that he’s not entirely stuck in the past like Baron Arminio; like Cosimo, he, too, can immerse himself in things like this that look to the future. Cosimo’s desire to figure out who these spies might be speaks to his desire to protect his community—which at this point, if it includes Freemasons, means that he feels duty-bound to investigate any interlopers in the best way he can (that is, from the trees). In this sense, Cosimo’s spot in the trees allows him to look out better for his community.
Father Sulpicio announces himself as a Jesuit, Cosimo announces himself as a Freemason, and the two Spaniards introduce themselves as Don Calisto and Don Fulgencio, also Jesuits. Cosimo notes that the pope recently dissolved their order, but Father Sulpicio announces that the Jesuits have formed an armed militia to combat new ideas. They draw swords and Cosimo runs to a sheet strung up between trees to catch nuts. Father Sulpicio joins him, declares that Ursula died in a convent (which Biagio thinks is a lie), and Cosimo stabs his adversary in the stomach. From then on, people think Cosimo is a Freemason.
Again, the idea that the Jesuits are fighting against new ideas shows that they’re fighting directly against Enlightenment ideas that challenge their hold on their power. More generally, this war between the Enlightenment and the Jesuits suggests that in some senses, Baron Arminio was right to distrust the Jesuits—and may have been more revolutionary than Cosimo ever gave him credit for.
Because of the secrecy surrounding Freemasonry, Biagio doesn’t have the opportunity to learn much about Cosimo’s dealings with the local lodge. Some talk about Cosimo as though he strayed later in life, but it’s also possible that Cosimo founded the lodge in Ombrosa. For one, early meetings took place in the middle of the night in the woods, and it’s possible that Cosimo received Masonic writings from his friends abroad. It’s also possible that Freemasonry had been around for a while before Cosimo stumbled upon a meeting, and his intellect made him useful to the lodge.
The idea that Freemasonry would’ve appealed perfectly to Cosimo shows that there are definitely upsides to the fine line Cosimo walks by living in the trees but still keeping contact with other people. His isolation, given the logic of the novel, does mean that he’s not as entrenched in the corrupting power of society on the ground, which may have made him even more appealing of a member to the Freemasons.
Biagio admits he never understood why Cosimo loved associations so much after fleeing from society, but it always seemed as though the more time he spent in the trees, the more he wanted to relate to other people. Cosimo throws himself into forming new groups, but he’s seldom able to follow through. He wants to create a universal society, and his attempts often include meetings that take place at night where he preaches about establishing a world republic of equals. Masonry thus appeals to Cosimo. Eventually, an English Freemason is shocked to discover the lack of a proper lodge and insists on sending money to build one. Cosimo unmasks Father Sulpicio after the lodge is built. Biagio suspects that Cosimo was aware that he couldn’t continue with Freemasonry, since he had no interest in building or living in houses.
In many ways, Freemasonry represents an ideal avenue through which Cosimo could continue to pursue Enlightenment ideals: it’s a group, it focuses on spreading Enlightenment ideas of government, and its beginnings take place in Cosimo’s backyard. When he distances himself from the Masons, however, it shows that Cosimo adheres too closely to his principles to be able to see any value in veering a little in the name of the common good. Regardless, Biagio’s tone suggests that Cosimo did a lot of good, commendable work through the Masons.