In 2000, Harvard University professor Robert D. Putnam published Bowling Alone: The Collapse and Revival of American Community. Its roughly 500 pages charted the unraveling of American social and civic groups and warned of the threat that posed to personal and civic health. Pete Davis thought the book was a downer when he studied it as a student in Putnam's "Community in America" class in 2010. He and his peers were feeling good about how things were going in the country, while Putnam was pointing out that fewer Americans were going to church, joining the PTA, singing in choral societies and having picnics. They were bowling, but not in leagues. The resulting decline in so-called "social capital," Putnam said, posed a threat to democracy. Ten years later, as the trend continued, Davis, a writer and cofounder of the Washington, D.C.-based Democracy Policy Network, realized that Putnam was right to be concerned. Democracy was in trouble, and Davis decided it was time to reconnect with his old professor. The result is the 2023 award-winning documentary Join or Die, which comes to Burlington's Fletcher Free Library on Friday, October 4. Putnam will participate in a post-screening discussion. Davis and his sister, Rebecca Davis, a former producer for NBC News and Vox's Netflix show "Explained," codirected and coproduced the film. Join or Die features interviews with former secretary of state Hillary Clinton, U.S. Secretary of Transportation Pete Buttigieg and U.S. Surgeon General Vivek Murthy and spotlights six community groups across the country. Chad Ervin, co-owner of Montpelier's Well Told Films, edited the documentary. Putnam, 83, figures he has spoken to more than 300,000 Americans in the past 25 years, a one-man prophet trying to redirect his country. The film takes his message to a wider audience — he now gets five to 10 speaking invitations a day — "so I'm hopeful," he said. Putnam talked with Seven Days from the study of his Jaffrey, N.H., home, looking across his pond toward Mount Monadnock. You're credited with creating the term "social capital." What is it, and how does it affect individuals and society? I did not actually invent the term "social capital," but I guess it would be fair to say I popularized it. The core idea is super simple: It is that social networks have value. They have value to the people who are in the networks. If you're in a…